The first thing I did to my Fazer was stick an extender to the mudguard with silicone. Twenty years and 200,000 miles on it's still firmly in place.
I wouldn't worry about the colour, black is well camouflaged against the tyre so it doesn't really notice. (OK, mine's a black bike, but I've seen plenty of red, silver, blue and brown Fazers with black extenders and they don't look any the worse for it.)