I dunno about anyone else, but when i recieve the barrier buff it looks like my health gauge just lost a massive amount of health. I know that the health gauge displays the barrier hp's above in yellow and that the pool appears in white/yellow, (instead of black when you lose health) but i think its the way the HP gauge drops down so that it looks like i've lost a ton of hp's.
This has resulted in me using my healing skill numerous times, in panic that I've atually lost health.
I think a better way to do this would be to make the barrier gauge in a blue color (or light blue) and have it fade out as it wears off (keeping the health pool static). Instead of the health pool gauge plummeting the same way it does when you take damage.