I removed mine to paint the brackets where the paint was slightly flakey - dead easy - one nut to undo.
With regard coating them black I don't know. Chrome won't paint will it? Plastic coat them? - there is a plastic coating in halfords that canbe peeled off if req - not used it myself - but might be good to trial to see if you like them black.
Then there is the question of matt/satin/gloss finish as well - I expect a paint expert will be along to offer an insight......
