That's definitely wrong in my case and for other colourblind people I know (I don't know many).
It felt pretty normal

My parents first noticed it when I was about 3 and wasn't sure about the colours of the chairs at kinder garden. They had a couple of different ones, I could tell they were different, but couldn't tell which was which. Then I noticed I sometimes got them confused e.g. I thought a dog cartoon in a book we had was green, etc.
Like one of the posters above, when someone finds out I'm colourblind they often start pointing at things and asking what colour they are. Unlike that poster, I don't hate it, but don't especially like it either. I just don't mind.
The only really bad experience, which I only had happen once, was in one camp. Someone was playing a game of naming clours and then finding things in the room that are that colour. Someone said yellow or green and I pointed at something that was the other colur. He got mad that I was wrong! That was still before I really knew being colurblind is.