I wear my good ol' jeans, a brown outdoor jacket I got from Cabelas for $100, and my Tilly hat...and I have no problem getting opportunities on elk and deer.
For bowhunting, yeah, camos make sense.
But I think the current camo fad has far more to do with marketing than actual practicality, IMHO.
An aside...
I just bought a pair of jeans (Dakotas from Mark's Work Warehouse) that are water repellent. Saw that on the label and snagged 'em to try out this hunting season.
My motto, if I can't do it in jeans, it ain't worth doin'!