My dad's colour blind - we don't let him go clothes shopping on his own. He's red/green blind, and also struggles with colours close together in patterns, like in tartans, and has no idea about what matches, tones or clashes. My ex is even worse, sees all sorts of colours wrongly. I was looking for a specific pink top in a shop once and he kept trying to point me towards the blue ones, swearing they were the ones I wanted. It caused a problem when we went on holiday and he picked up an almost identical suitcase to his - his was black with green trim, I think, and he picked up the same case but with lilac trim, and didn't notice till he tried to unlock it in the hotel.