>No idea how red/green blindness works in those grey (on grey) areas ;-)
Perhaps it's all actually gray? Just look at any street nowadays, and you'd think you're color blind - about 90% of the cars are the pavement color, just metallic.
Just to be true to my word, I never bought a gray car. Went burgundy, blue, dark ink blue, sky blue. Because nothing decent was offered in cyan, turquoise or violet.