Editing Pigment (section)

===Computer swatches===
The appearance of pigments in natural light is difficult to replicate on a [[computer display]]. Approximations are required. The Munsell Color System provides an objective measure of color in three dimensions: hue, value (or lightness), and chroma. Computer displays in general fail to show the true chroma of many pigments, but the hue and lightness can be reproduced with relative accuracy. However, when the gamma of a computer display deviates from the reference value, the hue is also systematically biased.

The following approximations assume a display device at [[gamma correction|gamma]] 2.2, using the [[sRGB color space]]. The further a display device deviates from these standards, the less accurate these swatches will be.<ref>{{cite web |url=http://www.gamma-sci.com/dictionary-color-terms/ |title=Dictionary of Color Terms |publisher=Gamma Scientific |access-date=25 June 2014 |url-status=dead |archive-url=https://web.archive.org/web/20140820184550/http://www.gamma-sci.com/dictionary-color-terms/ |archive-date=20 August 2014 |df=dmy-all}}</ref> Swatches are based on the average measurements of several lots of single-pigment watercolor paints, converted from [[Lab color space]] to [[sRGB color space]] for viewing on a computer display. The appearance of a pigment may depend on the brand and even the batch. Furthermore, pigments have inherently complex [[reflectance]] spectra that will render their color appearance<ref>{{cite web |url=http://helloartsy.com/color-appearance/ |title=Color Appearance |website=Hello Artsy |date=2 September 2013}}</ref>{{Better source needed|reason=Very little information here, let alone references to reliable sources.|date=February 2018}} greatly different depending on the spectrum of the [[standard illuminant|source illumination]], a property called [[metamerism (color)|metamerism]]. Averaged measurements of pigment samples will only yield approximations of their true appearance under a specific source of illumination. Computer display systems use a technique called chromatic adaptation transforms<ref>{{cite web |url=http://www2.cmp.uea.ac.uk/Research/compvis/ChromaticAdaptation/ChromaticAdaptation.htm |title=Chromatic Adaptation |publisher=cmp.uea.ac.uk |access-date=16 April 2009 |url-status=live |archive-url=https://web.archive.org/web/20070929155854/http://www2.cmp.uea.ac.uk/Research/compvis/ChromaticAdaptation/ChromaticAdaptation.htm |archive-date=29 September 2007}}</ref> to emulate the [[correlated color temperature]] of illumination sources, and cannot perfectly reproduce the intricate spectral combinations originally seen. In many cases, the perceived color of a pigment falls outside of the [[gamut]] of computer displays and a method called [[color management|gamut mapping]] is used to approximate the true appearance. Gamut mapping trades off any one of [[lightness]], [[hue]], or [[colorfulness|saturation]] accuracy to render the color on screen, depending on the priority chosen in the conversion's [[International Color Consortium|ICC]] [[rendering intent]].
<!-- Current source of swatch information: http://www.anthus.com/Colors/NBS.html (gone) and https://www.handprint.com/HP/WCL/huepurity.html -->
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! <!-- A color swatch -->
<div class="thumb tleft">
<div style="width:125px;">
<div style="width:117px; height:50px; background:#990024; color:white;">#990024</div>
<div class="thumbcaption">[[Tyrian red]]<br></div>
</div></div>

! <!-- A color swatch -->
<div class="thumb tleft">
<div style="width:125px;">
<div style="width:117px; height:50px; background:#e34234; color:white;">PR106 – #E34234</div>
<div class="thumbcaption">{{Nowrap|[[Vermilion]] (genuine)}}</div>
</div></div>

! <!-- A color swatch -->
<div class="thumb tleft">
<div style="width:125px;">
<div style="width:117px; height:50px; background:#ffb02e; color:white;">#FFB02E</div>
<div class="thumbcaption">[[Indian yellow]]</div>
</div></div>
|}
{| border="1" cellspacing="0"
|-
! <!-- A color swatch -->
<div class="thumb tleft">
<div style="width:125px;">
<div style="width:117px; height:50px; background:#003baf; color:white;">PB29 – #003BAF</div>
<div class="thumbcaption">[[Ultramarine]] blue</div>
</div></div>
! <!-- A color swatch -->
<div class="thumb tleft">
<div style="width:125px;">
<div style="width:117px; height:50px; background:#0b3e66; color:white;">PB27 – #0B3E66</div>
<div class="thumbcaption">[[Prussian blue]]</div>
</div></div>
|}