We should be given the ability to preview dye colors we haven't unlocked. As it is many of the hues are very similar, and not being able to customize our look by being able to see all our options lessens the desire to try to get achievements specifically for the dyes. You already allow us to quickly see which achievement is needed for a locked color, why not let us preview the locked colors so we know if it's worth trying for the achievement?
Rose - AD - Khajiit Nightblade
Modest Argonian Maid - EP - Argonian Sorceror
Man Shen - AD - Altmer Templar
Largesse - DC - Dunmer Dragon Knight
Which-Way-To-The-Beach - AD - Argonian Sorceror