I'd always known my father is red/green colour blind (they both look like shades of sepia to him, as far as I can tell), but until today I'd never really well thought about how that affects him. We were talking about sunsets, and he mentioned that they looked grey to him; his eyes don't see the pink or orange hues. Brake lights on cars are dull, traffic lights are problematic and he can never find a matching tie. He compensates when buying clothes by getting the assistant to pick out only grey or blue colours, and he has the gardener choose the plants. Food looks unappetizing, as his eyes turn green, orange, purple and reds into brown. He can't even see ketchup properly! Must be like living in a 2-dimensional world.