Really do think that they could have better made use of the coating systems.
Namely:
Texture Filters: I see some armor coatings have a prestene look while others have a used and abused appearance. Personally, I feel this should have been an element to all armor coatings as a seperate option to really affect the appearance, you cool look shiny, dull, plastic, damaged or whatever but retain the colors and patterns.
Patterns: Instead of having armor coatings with different pattern/color mixes, why not just have a base pattern (this includes the different armor part coloring), you’d have even more combos of really cool patterns like the camo.
Colors: Color sets would appear as they do but not affect the pattern design or filter. They’d be three parts to create the overall armor and this probably wouldn’t change much in regards to the current system design.
I would personally like a per part basis but just using the current design I think these tweaks would ultimately make every armor color, pattern and filter an even worthwhile investment to players looking to spend time and money to customize their spartans.