Most of customers have graphic deign. Those color can be fixed in the script or the variable editor. The expression of the variable can be a RGB function or a hexa code.
For the moment (up to version September 2019), those color variables can't be apply on dimension value or measure color. It's shame that a color variable can't be reuse for custom color, specially for a master measure.
The color panel is missing a expression editor to apply our custom color or condition.