Essentially, yes. Each shade has a number ("Battleworn Blue I") that will shade anything with that number (you find the number in the upgrade menu. Almost all beta gear was Shade I). If you wanted just the helmet to be yellow and the rest to be a black shade you would need a spare helmet. You apply equip the yellow, everything you are wearing turns yellow, you switch the yellow helmet with a dummy helmet, you equip black shader, everything turns black, you then equip the yellow helmet. You now have a yellow helmet and black gear.