yes that would be ok, but I cant imagine it looking any good, as they dont use paint, its coloured rubber hence why they take out about 1mm then fill it with coloured rubber, as said above this is illegal im basically all states, it weakens the tyre apart from it being illegal im sure it would void any insurance as your not running proper load rated tyres, I haved done it with a fat white perminant marker works ok if the tyre doesnt have much writeing etc on the walls, looks good from a distance, but im talking old crappers not anything like a xr6