So we don't have a vanity system (no the single slot disguise is not a vanity system).
Some players like to mix and match armour, the problem is, depending on armour weight, colour will vary. I've noticed most armour pieces are no more than 2/3 colours. So my suggestion would be - have all armour pieces 'colour match' to the central piece - the main body. This way when mixing and matching it won't look so odd.
Allow cross-platform transfers and merges