I bet I know just which chrysler charcoal you are thinking , its a coarse high metallic , I use it under my Kandies alot , with all that flake it sure makes Kandys POP

I usually do a spray out on a 12"x12" panel with my color then mask off for a few color selections for stripes , then clear it and polish it , take it out side and see which ones I like .

Having a mix bank at work helps too I get to play mad paint scientist