I did enough shooting of the other sort stood in hedgerows etc wearing the your typical brown or green Barbour gear which was more than enough cammo, you often couldn't pick out other shooters against the background.
Obviously, white lenses are bad news and need covering , but the thing which birds will see is large areas of skin - your face and arms, they appear practically flourescant and shine as far as the birds are are concerned, so a hat pulled well down on your forehead is a big help. I can't be doing with face veils but again, they're a huge help.