Oh, that's like my Bubbles!
OK, I don't know any codes, but here's the real way: Breed a shiny chao (ie: Shiny white) with a metallic chao (one that you can get in Sonic advance, or Sonic Advance 2), that'll make a transparen chao. Then, make it reincarnate twice (meaning that it has to go back to it's egg form twice), once you hatch it, feed it one of every animal, and maybe some fruit (do NOT use the fake-feed glitch), and make sure its love is at least almost equally balanced between hero and dark. Then, it'll go into a cocoon, an ttransform into an Ultimate Light (AKA Neutral Chaos) transparent chao.
Where's my sig?