Coat colors

Since DuckHunt V4.1, when buying a coat in the shop you'll be given a randomly colored coat. Additionally, with prestige level 2 or more, you are even able to select a specific color yourself (dh!shop coat <color>).

Every color will give you a small, different power up.

White coat

A useful coat when it rains

Orange coat

Better visibility: Increase your chance to frighten ducks, and reduce your chance to get shot by another hunter.

Camo coat

Lower visibility: Less chance to frighten ducks.

Blue coat

Lucky find: Increase your chance to find items in bushes.

Red coat

Hungry for blood: Increase your murder skills, reduce murder penalties.

Yellow coat

Sun powers: Mirrors are less effective against you.

Dark green coat

Farming skills: Clovers give you one more experience point.

Black coat

Secret service: Sabotages are cheaper.

Light blue coat

Sea powers: You are immune to water buckets.

(As do all the other coats, so this one is indeed useless)

Pink coat

Power of love: You can't kill players with the same coat color.