Allow us to add patterns as a replacement for skins. When you select an armor, you can choose a pattern and color said pattern. There can be a bunch of patterns like camo, stripes, etc.
So basically how DOOM 2016 did it, with being able to unlock tons of extra patterns as well.
I just hope it'll be a soft reboot for the franchise as a whole in a way, it'll be the first brand new full, complete Halo experience on PC since H2 Vista, (MCC is a collection of older titles, doesn't count in that respect), so the PC players deserve a good introduction to the franchise, as they may be the key to reviving interest in Halo as a whole alongside the MCC release, but for newer titles in the series instead.