How Lab-Grown Fancy Diamonds Are Colour Graded: Nine Descriptors and Laboratory Methods
Updated: Oct 18
A lab-grown diamond described as Fancy Vivid Pink carries two pieces of colour information: Pink identifies the hue, while Fancy Vivid describes a region defined by tone and saturation within that hue. Formal fancy-colour grading compares a diamond's face-up colour with reference materials under controlled lighting and viewing conditions, then records the result using standard terminology.[1][2][3]
This vocabulary gives pink, yellow, blue and other coloured diamonds a shared descriptive framework while allowing for differences between individual stones. Two diamonds described as Fancy Vivid Pink can still vary in hue direction, tone and colour distribution. Natural or laboratory-grown origin, and evidence of colour treatment, are reported separately.[3][4]
Figure 1 A complete colour name contains an intensity descriptor and a hue. Concept illustration.
Contents
1 Nine Fancy-Colour Intensity Descriptors
Where the nine terms apply
GIA's commonly used fancy-colour intensity descriptors include the nine terms below. They describe combinations of tone and saturation, and their applicability varies with hue. The English wording is the clearest reference when checking a report.[1][7]
Figure 2 All nine descriptors illustrated in colour; applicability depends on hue.
The illustration uses a pink hue direction to demonstrate all nine terms. The upper row shows very weak to light colour; the middle row illustrates Fancy Light, Fancy and Fancy Intense; the bottom row illustrates vivid, deep and dark appearances. These last three are separate descriptors. The terms available for an actual diamond depend on its hue.[1][2]
Descriptor | General visual description |
|---|---|
Faint | Extremely weak colour in an applicable hue |
Very Light | Very pale but discernible colour |
Light | Colour within the applicable light range |
Fancy Light | A lighter fancy-colour region for that hue |
Fancy | A corresponding region of tone and saturation within the hue |
Fancy Intense | Generally a stronger colour appearance |
Fancy Vivid | Generally a vivid, strongly expressed colour |
Fancy Deep | Deeper tone combined with corresponding saturation |
Fancy Dark | A darker colour region |
Each descriptor covers a range
An intensity descriptor covers a region of colour space. After comparing a diamond's hue, tone and saturation with a reference system, graders place it within the corresponding region. Subtle differences remain possible within the same grade.[2]
For example, two Fancy Pink diamonds may differ slightly in hue direction or tone. Yellow, pink, blue and other hues also have different applicable ranges and boundaries. Reading the full colour name together with its intensity descriptor gives a more complete picture of the colour position being described.[1][2]
2 How Hue, Tone and Saturation Work Together
Three attributes of colour
Fancy-colour grading describes colour through hue, tone and saturation.[7]
Figure 3 Hue, tone and saturation describe different attributes; the saturation row keeps a similar tone.
Hue identifies the colour direction: yellow, blue, pink, or a mixed direction such as purplish pink or greenish blue. Tone describes relative lightness or darkness. Saturation describes colour strength: at a similar tone, a greyish pink appears more muted, while a pink with stronger colour expression appears more vivid.
When looking at two pink diamonds, separate how light or dark the overall colour looks from how strongly the pink is expressed. The first observation concerns tone; the second concerns saturation. A darker pink is not necessarily more saturated, and a lighter pink can still have a clear colour presence.
From the D–Z scale to face-up fancy colour
The D–Z scale commonly used for white diamonds primarily describes the absence of colour within the normal colour range. D–F is colourless, G–J is near colourless, and subsequent groups show increasingly noticeable pale body colour. Both natural and lab-grown diamonds can exhibit these colours; the report used depends on the laboratory and service.[5][6]
Fancy-colour grading focuses on face-up colour. GIA's fancy-yellow descriptions begin at Fancy Light, while paler yellow falls within D–Z. Other hues, including pink, blue and green, can receive fancy-colour descriptions even when very pale. Yellow and pink therefore have different starting points and applicable terminology.[1][2]
For examples across both origins, see What Colours Do Diamonds Come In? Natural and Lab-Grown Diamond Colour Ranges.
3 Colour Families and Complete Colour Names
Terminology varies with hue
Fancy diamonds include yellow, pink, red, orange, green, blue, purple, brown, grey and black. The following examples draw on GIA's published research and guidance. The available intensity terms and their ranges should be understood within the laboratory's method for each hue.[10][11][12][13][16][17]
Figure 4 Conceptual colour families; red and black have specific terminology discussed in the text.
Colour family | Representative descriptions or research examples | Reading points |
|---|---|---|
Yellow | Fancy Light Yellow, Fancy Intense Yellow, Fancy Vivid Yellow | GIA's fancy-yellow range starts at Fancy Light; paler yellow is graded on D–Z |
Pink | Light Pink, Fancy Light Pink, Fancy Intense Pink, Fancy Vivid Pink | Tone, saturation and purple, orange or brown modifiers affect the appearance |
Red | Fancy Red and Fancy purplish red | GIA uses Fancy as the sole intensity descriptor when red is the main hue |
Orange | Fancy Orange, Fancy Vivid Orange | The full name may include yellow, pink or brown directions |
Green | Fancy Intense yellow-green, Fancy Vivid yellow-green | Retain the full hue name and check the colour-origin conclusion separately |
Blue | Fancy Light Blue, Fancy Intense Blue, Fancy Vivid Blue | Grey or green components, tone and colour zoning affect the appearance |
Purple and violet | Fancy Purple, Fancy Vivid Purple | Purple and violet indicate different hue directions; read the full English name |
Brown | Fancy Brown and modified brown descriptions | Trade names such as Champagne or Cognac should be checked against the formal description |
Grey | Faint Gray through Fancy Dark Gray | Bluish grey and greyish blue can have different main hues |
Black | Fancy Black | GIA uses a single black colour grade; colour appearance and surface condition remain relevant |
GIA's red-diamond research explains that the tone and saturation range described with red as the main hue is narrow, so only Fancy is used. Black diamonds likewise have the specific Fancy Black description. When reading natural or lab-grown reports, use the issuing laboratory's service and terminology as the reference.[10][13]
Main hue and modifying colours
In Fancy Vivid Purplish Pink, Fancy Vivid is the intensity descriptor, Purplish is the modifying colour and Pink is the main hue. Purplish pink and orangy pink can have the same intensity term while creating different warm or cool colour combinations.[7]
Figure 5 Reading Fancy Vivid Purplish Pink through a conceptual example.
Figure 6 Pink remains the main hue while modifiers change the warm or cool direction.
All four illustrations retain pink as the main hue, with purple, orange or brown components changing the colour direction. A modifier can visibly affect warmth and colour harmony even when the main hue remains the same. Published research on natural pink diamonds records these hue directions.[17]
Greenish Blue and Bluish Green follow the same principle: the first is predominantly blue with a green component; the second is predominantly green with a blue component. The complete name is more informative than simply calling either stone blue or green.
Figure 7 Greenish Blue and Bluish Green have different main hues.
Read the colour name alongside Color Distribution. Even and Uneven describe the distribution seen face-up and help explain differences between stones with similar colour descriptions. Localised zoning and the overall balance are also worth examining in person.[2][6]
4 Reading Natural and Lab-Grown Fancy-Colour Reports
Natural origin and natural colour are separate findings
A natural diamond can undergo artificial treatment to change its colour after formation. When assessing a natural fancy diamond, check both its natural origin and whether its colour is natural, then read the full colour description and distribution.[4]
Colour-origin determination is particularly significant for green diamonds. GIA research explains that both natural radiation and artificial irradiation can produce green colour, and that some samples are extremely difficult to resolve. A professional laboratory reaches its conclusion through combined gemmological testing.[12]
In-person observation can then consider zoning, tone and the balance of face-up reflections. These observations explain the wearing appearance alongside the report's origin and colour findings.
Growth method and treatment information for lab-grown diamonds
Lab-grown fancy diamonds have the diamond crystal structure that hosts their colour. Some colour develops during growth; some is adjusted through post-growth treatment. IGI's official explanation discusses high-pressure high-temperature treatment, irradiation, annealing and combined treatments, including changes at the lattice level.[14]
A verifiable example is IGI report LG627421064, for a 1.54 ct Fancy Vivid Pink CVD-grown diamond with indications of post-growth treatment. Colour, growth method and treatment information appear as distinct findings in the same report.[15]
Check the report number through the laboratory's official verification system, then match the weight, shape, measurements and any verifiable girdle inscription. For colour observation, consistent lighting, background and comparable exposure help reveal modifiers, tone, distribution and the appearance as the diamond moves.
Read GIA and IGI findings within the report service
IGI's fancy-colour reports cover natural and lab-grown diamonds and describe their colour and relevant gemmological information. Shared terminology supports communication; comparison between laboratories should also consider their methods, report contents and the actual stones.[4]
GIA currently offers a full Laboratory-Grown Colored Diamond Report and a colour-identification report. The full report includes quality information and a plotted clarity diagram; the identification service describes colour and distribution. Both assess growth type and post-growth treatment. These are separate services from GIA's current Premium/Standard quality assessment for colourless to near-colourless lab-grown diamonds.[6]
For more on reports, see Lab-Grown Diamond Certificates: GIA, IGI and NGTC. Growth principles are explained in our CVD and HPHT guide.
5 Laboratory Grading Procedures and Instruments
Establishing identity and colour-origin information
On receipt, the laboratory establishes the sample's testing record, confirms its material and natural or laboratory-grown origin, and examines treatment-related features. Microscopy, spectroscopy and imaging contribute to this work. IGI's fancy-colour report guidance includes origin screening, gemmological assessment under controlled conditions and treatment disclosure.[4]
Identification and colour grading provide different information. Fancy Vivid Pink describes colour appearance; Laboratory Grown identifies growth origin; a post-growth-treatment comment records detected treatment indications. All three findings should be read together.
Observing face-up colour under controlled conditions
GIA's published method describes a viewing box that excludes external light, controlled daylight illumination, and a grooved, matte, non-fluorescent white tray. The diamond is positioned table-up, with a prescribed relationship between illumination, diamond and line of sight, so that samples can be compared consistently.[2][18]
GIA's 1994 method study specifically documented a Macbeth Judge II viewing box and a daylight simulator of approximately 6500K. This historical equipment example illustrates the importance of lighting specifications. The broader requirements are controlled spectrum, illumination, background and viewing geometry; a matching colour-temperature number alone does not reproduce the complete conditions.[3]
Grading also requires normal colour vision and continuing training. Diamonds produce reflections, fire and contrasting facets. Graders identify the characteristic colour representative of the stone and adjust their observations according to the method, separating transient surface reflections and other optical effects from the principal colour.[2]
Bracketing colour with reference materials
Once the characteristic colour is established, graders compare the diamond beside references of known colour position to bracket its hue, tone and saturation. The aim is to locate a region of colour space rather than to find one reference that looks identical to every test stone.[2]
Published GIA research documents the use of reference coloured diamonds and Munsell colour chips. Diamonds reproduce a transparent faceted appearance, while colour chips assist in expressing positions within colour space. Laboratories apply their own methods and reference systems; ordinary printed charts and phone screens are useful for colour communication.[2][3]
Figure 8 A summary of identification and colour-grading work; details vary by sample and laboratory.
Tools for colour grading and origin identification
Visual assessment and spectroscopic testing work together within a complete examination. Visual assessment establishes the colour description; spectroscopy and imaging investigate lattice defects, growth features and treatment indications. The following tools are documented in public gemmological research. The combination used depends on the sample.[3][8]
Figure 9 Six types of equipment with different roles in visual grading and origin identification.
Tool or equipment | Main observations | Relationship to colour grading |
|---|---|---|
Controlled-light viewing box and colour references | Face-up hue, tone and saturation | Directly support visual grading and colour positioning |
Gemmological microscope | Inclusions, growth patterns and colour zoning | Help interpret distribution and sample identity |
Fourier-transform infrared spectroscopy: FTIR | Impurity-related absorption, including nitrogen, and diamond type | Inform origin assessment and further testing |
UV–Vis–NIR absorption spectroscopy | Absorption at different wavelengths and colour-related defects | Investigate colour mechanisms and treatment-related features |
Photoluminescence spectroscopy: PL | Defect emissions excited by a laser | Support interpretation of growth and treatment evidence |
Deep-ultraviolet fluorescence imaging | Growth-sector and luminescence patterns | Help distinguish natural and laboratory growth features |
Absorption spectra can show which wavelength regions particular colour centres absorb; PL can reveal trace defect signals. These findings are interpreted together with microscopy and imaging to address complex origin questions. Laboratories do not publish every configuration for every sample, and equipment models cited in research should be understood in their publication context.[8]
After colour assessment and related identification work, the laboratory reviews its findings and issues the relevant report. IGI's published grading process describes independent colour opinions from multiple gemmologists, with the required agreement reached before a grade is finalised.[9]
6 How RAGAZZA Selects Lab-Grown Fancy Diamonds for Jewellery
Natural fancy-colour appearances as a reference
RAGAZZA gives priority to lab-grown fancy diamonds whose colour regions and grade appearances have corresponding references among known natural fancy diamonds. We consider the complete combination: main hue, modifiers, tone, saturation and the reported grade, rather than a yellow, pink or blue label alone.
For pink, references include pale pink, purplish pink and orangy pink directions seen in natural fancy diamonds. Blue references include greyish or greenish components and different tones; yellow references include bright yellow and warmer orangy yellow. We aim to continue the aesthetic language established by natural fancy diamonds, choosing subtle colour relationships suited to long-term wear.
This is the practical basis of what we mean by a natural fancy-diamond aesthetic: colour and intensity have real natural references, while laboratory-grown origin and treatment information remain clearly disclosed. The grade gives a direction; the individual stone shows how that colour appears in a faceted diamond.
Figure 10 The first two columns show overlapping appearances; the third differs from that row reference.
Overlap means that the candidate lab-grown diamond's complete colour appearance has a close reference among known natural fancy diamonds. In each row, the first two columns illustrate similar main hue, modifiers, tone and saturation. The third deliberately changes some of those attributes to show a departure from that row's reference. Published natural-diamond research provides examples of pink, blue and yellow colour regions.[11][16][17]
In practice, we extend the reference set across the relevant natural colour family and consider the reported grade together with appearance. Priority goes to harmonious lab-grown colours with clear natural appearance references.
From an individual stone to a coordinated jewel
A colour grade defines a range; selecting a stone for jewellery also requires assessment of its distribution, transparency, reflections and facet contrast. RAGAZZA checks the report against the actual appearance and selects stones for the design, metal colour and overall palette. Within those aesthetic and quality requirements, we tend to favour some of the colour appearances covered by Fancy Intense and Fancy Vivid.
For earrings, bracelets and multi-stone rings, matching also involves warmth, colour strength and tone across the stones. Even closely named colours need to be checked together. This coordination forms part of RAGAZZA's stone-selection and matching work.
Figure 11 RAGAZZA checks individual colour, design palettes and matching across stones.
Explore RAGAZZA's pink-diamond jewellery, blue-diamond jewellery and yellow-diamond jewellery to see colour combinations in finished designs, or book a viewing to examine the colours and corresponding report information.
7 Fancy-Colour Grading Questions and Answers
Q1 Can lab-grown fancy diamonds receive Fancy colour descriptions?
Answer: Yes. IGI's fancy-colour reports cover natural and lab-grown diamonds, and GIA also offers laboratory-grown coloured-diamond reports. Fancy terminology describes colour, while natural or laboratory-grown origin is disclosed separately. Read the findings within the issuing laboratory's specific service.[4][6]
Q2 Why can diamonds with the same colour name look different?
Answer: A complete colour name and intensity descriptor identify a range. Subtle colour differences remain possible within that range, while distribution and face-up contrast also affect appearance. The report provides a standardised description; the actual stone reveals those details.[2]
Q3 Does a Fancy grade prove natural origin or natural colour?
Answer: A colour grade describes appearance. Whether the diamond is natural or lab-grown, and whether its colour has been artificially treated, require separate gemmological findings. Check those conclusions and comments independently of the colour grade.[4][8]
Q4 How is post-growth treatment recorded on a lab-grown fancy-diamond report?
Answer: Laboratories test and record growth and treatment information according to the report service. The IGI pink-diamond example discussed here identifies laboratory-grown origin, CVD growth, Fancy Vivid Pink colour and indications of post-growth treatment. Each field communicates a different characteristic and should be read with the others.[4][15]
8 References
Prepared by RAGAZZA DIAMOND. Sources checked on 18 October 2026. The illustrations explain grading concepts; they are not matched real stones, colour-grading standards or official grade boundaries. The following official sources describe the underlying methods and report services.
