If you aren't set on round confetti, then just roll out a 50/50 fondant/gumpaste mixture extremely thin. let it dry a little to firm up and then cut small strips, then cross cut them on the bias to make "diamond" shapes or cut perpendicular to make "squares". you could also make some curliques by wrapping strips of these same colors around straws and letting dry.
The fondant/gumpaste could also be dusted with pearl dust to make it shiny on one side and plain on the other for another effect.
Happy Caking!