Just my experience: I was dead set on getting the navy GR8 (which, from what I can tell from your pic, is a LOT darker in color and more traditional looking than your helmet) and was forcefully talked out if it by literally everyone I encountered. I was in line with it trying to buy it at Dover and the girl ringing me up wouldn’t let me buy it! “You show hunters?” “Occasionally, yes.” “Then you should not be wearing this helmet.”
I was tempted to buy it just for spite but the reaction everyone (my trainer, barnmates, random strangers!) had to the idea of a navy helmet was so extreme/aghast that I decided I’m not a good enough rider to push the envelope with a nontraditional helmet color.
Of course, I had decided to go for the navy helmet in the first place at the encouragement of COTH…
TL;DR: while COTH may tell you yes, IME it’s not as accepted out in the “real world.”