Colour blind just means you can't fly at night. Which isn't any real problem for a pleasure pilot.
Right sims. I am a reasonably experenced instructor and in my experence they do more harm than good until you have been taught properly what to do.
They are good for practising instruments and the like but fall down on the visual flying skills.
It means the instructor has a blank sheet of paper to work with instead of having to erase bad habits as they go along if you don't use one.