The color settings are slot based ... like Schoolwear_OuterTop_Set1, Swimwear_BikiniBottom_Set2, Evening_Dress_Set2, Nighttime_UnderwearTop_Set1, etc...
The color palette is global for all outfit slots ...
Once I realized that ... I gave up on customizing the colors ... before it gets messy again, I rather stick with the given color selection/palette ...