[MetalMilitia]

ust because you've not seen something it doesn't mean you don't know what it looks like. A blind person probably has a pretty good mental image of what, say, a dog looks like from hearing them being described, touching them etc.

Once you know kind of what things generally look like your brain will fill in the gaps. If you consider some of your most vivid dreams you'll probably find that many of the places you go or people you meet are not taken from real life experiences but your brain still knows what they should look like from the range of experiences you've had throughout your life.

ADDED: The only thing which might be radically different from a non-blind person would be, as you say, colour because I don't know if you can really explain a colour without the frame of reference of other colours.