Don't do it before, you'll lose the colour under whatever sponsor/race livery the RM has. I don't think you can re-customise the car afterwards either...sorry.
Yes you can change the color anytime you want BUT if you paint BEFORE you'll loose it, and if you have just one it's not a good ideaDon't do it before, you'll lose the colour under whatever sponsor/race livery the RM has. I don't think you can re-customise the car afterwards either...sorry.
Convert first, the car will default to whatever RM color is after the conversion(usually white). Then you can apply whatever color on it. Note though that RM car usually have a "paint job" and the color will usually only apply to a portion of the car...