Opinions are like sphincters. Everyone's got one and they all . . . .
I would not paint until YOU find something that really moves you. You can always re-paint, but it's a PAIN in the ass.
Personally, I would not put a number on a bike, unless the number has some personal significance (lucky number, date you got divorced, whatever). The year of the bike doesn't seem to cut it. Just my $0.02!! I'm also not much of a yellow bike person but some people are.