Major
Active Hunter
Considering we don't know the filming conditions, the conditions the costumes were kept in, that's very possible. Also depends on how much the suits were washed as well. Color will fade naturally, and we also don't know if they made a specfic choice to aliter the color of the soft goods. Considering they changed every other aspect of the costume between ESB and ROTJ, that's a very real possibility. Prop makers love to change things...