This code system http://hl7.org/fhir/color-rgb defines many codes, but they are not represented here

<status value="active"/><experimental value="false"/><publisher value="FHIR Infrastructure"/><contact><telecom><system value="url"/><value value="http://hl7.org/fhir"/></telecom></contact><description value="RGB values for color. Valid codes are #RRGGBB where RR, GG, and BB are two letter hex codes, values 00..ff. codes are case insensitive. This code system does not define the 16million+ valid RGB codes (terminology servers will need code to support the RGB grammar)."/><jurisdiction><coding><system value="http://unstats.un.org/unsd/methods/m49/m49.htm"/><code value="001"/><display value="World"/></coding></jurisdiction><copyright value="[Copyright](https://www.w3.org/Consortium/Legal/ipr-notice) ©2022 World Wide Web Consortium. All Rights Reserved. This work is distributed under the [W3C® Software and Document License](https://www.w3.org/Consortium/Legal/copyright-software) in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE."/><caseSensitive value="false"/><compositional value="true"/><content value="not-present"/></CodeSystem>