This issue is for setting "Text Chat" preference can't be set in colors_base.xml so they can be set by skinners. The colors specifically are:
"AgentChatColor"
"IMChatColor"
"ObjectChatColor"
"llOwnerSayChatColor"
"BackgroundChatColor"
"ScriptErrorColor"
"HTMLLinkColor"
Leaving them in preference will cause them to contrast with different skinned color schemes.