Is it possible to consider removing all the coloured varients of materals, list all available as they are, carbon fibre. Plastic, etc. Then introduce purchasable litres of paint. Then use an overlay sort of option to be able to use a shape tool to paint voxels. This would mean better colour customisation and the Ability to change ship colour easily.
if noy a way to paint shapes, a paint voxel area option. Shape painting would be great to add that bit more authenticity to builds, make a ship look like metalic hull, bulkheads, warning markers, all that kinda cool stuff.