the composite is black and white out on 500's and 2000's I don't know why they changed it the 1000's had color. I will look for an old article telling how to modify it.
You wouldn't use the A1000's composite video by choice. It's bad, worse even than an a520.
On the a500/a2000 they had to generate the composite sync, adding the monochrome video to it is cheaper than colour. Without the colour signal interfering text will be more readable.
If you were doing video you'd get an expensive external broadcast quality convertor, and any mixing/genlock you'd want to do before the conversion.
If you had an A2000 then you'd normally also have a decent monitor. An RGB scart lead should be equivalent.
