Ralph McQuarrie Joe Johnston's original concept art for Boba Fett put the bounty hunter in an all-white costume. Although Fett eventually got a multicolored look, an early screen test showed him in the white outfit.
This video was posted on StarWars.com a while back, but now it has popped up again, this time on the Star Wars YouTube channel. The Empire Strikes Back assistant film editor Duwayne Dunham modeled the Boba Fett costume for this 1978 video (unfortunately in black and white) while sound designer Ben Burtt explains all the features of this version of the armor. By this time, they knew that Boba Fett would have multicolored armor.
[via The Retroist]