And if it was a green object which wasn't as colourful as a crayon, I could even think it was red. Here are two identical pictures of random dots. Well, that's what I see them as. If you're not red-green colour blind then you will see a green number 17 in the picture on the left. I still can't see it even after my fiance traced it out.
Colour blindness does have some advantages.
Our night vision tends to be much better than average. Yet very few companies or services give colour blind people any thought. It's very rude and very boring. I'm colour blind. See professional advice before acting on any information given.