I feel you on that point. I once hiked behind a guy whose pack was neon blue. For hours at a time in bright Florida sun It was thee burning itself into my retinas. I would close my eyes and still see that damned thing. We had to change the marching order.

Hikers and campers often floor into narrow tracts of land and a overly bright backpack, jacket or tent can pretty much ruin the view of scenic vista. It is sometimes termed 'visual pollution'.

My preferences are for drab earth colors. Deep greens and blues. Subdued reds. Gray, black and browns. OD green and browns are okay. Not quite military enough to be mistaken for a mall ninja but pretty nondescript and subdued enough to not catch the eye if you want to slip out the back.