I heard a song on Radio 3 the other day called "I used to be colour blind" and im sure they said it was Frank Sinatra singing it, does anyone know if he did sing it? it did sound like him singing it.
Tony Bennett recorded it, but he doesn't sound like Sinatra. There's a
track on Spotify by Jack Six that might be the one you're after, though he doesn't sound much like Sinatra either. You'll have to use the American spelling to find it - "color".