Document colors are are special color palette showing the used colors. Despite several issues it lacks on documentation.
Indeed. Documentation for "Document colors" can be added here (below the Custom Palette entry): https://help.libreoffice.org/7.2/en-US/text/shared/01/05210200.html?DbPAR=SHARED#bm_id37440771
Patch is ready to submit at https://gerrit.libreoffice.org/c/help/+/128032
Olivier Hallot committed a patch related to this issue. It has been pushed to "master": https://git.libreoffice.org/help/commit/16edeee7671a4dcbc23180e0d1829cbc1fbf2e92 tdf#146580 No info on Document palette
"The Document colors palette shows the colors used in the current document." found on page https://help.libreoffice.org/7.4/en-US/text/shared/01/05210200.html Therefore this seems to be fixed. What do you think Heiko?
Thanks Olivier. Note: We discussed whether the current shortcomings of this feature should be mentioned in the online help and Olivier decided against. Better to fix an issue than document it.