I too am colorblind. I can only notice two shield types. Yellow and blue. At least that is what it looks like to me. When I learned that there is a third i began to search for it but still can not see it lol. Here is something else I almost did. When you have an exotic armor/weapon equipped, all the other exotics of different types (helmet, gauntlet) are greyed out. If you have a green item that you picked up and wish to dismantle, the greyed out exotic looks green too. Luckily for me I read the word "exotic" halfway through dismantling. So, yeah, "greyed out" items need to be "greyed out" and dimmer. The idea is higher contrast.