In this undated photo, Packer legend Bart Starr runs with the ball as he tries to elude two Baltimore Colt defenders.
This is a very unusual Packer uniform in that it doesn't contain any gold. White from head to toe, with single blue stripes on the helmet and pants and blue Northwestern stripes on the sleeves and socks.
The all-white uniform was introduced by head coach Lisle Blackbourn, and replaced when Vince Lombardi took over the team in 1959. Starr came to Green Bay in 1956, so that helps us. According to the Packers' media guide, the white uniforms became commonplace in 1957, so that narrows it down to two possible seasons.