I wonder: Does this let you scale between colors or is it just light or dark? On systems that support it, I always end up deciding on a sort of light gray appea

I wonder: Does this let you scale between colors or is it just light or dark? On systems that support it, I always end up deciding on a sort of light gray appearance that's still darker than the typical Mac OS look. (And on CDE, I like the sand and teal ;-))