I have a team of shiny pokemon all lvl 100... i will also list how they look on XD in parenthesis, because they do look different in some cases.
Aagron- Where it is grey, white. Black areas are light blue. His eyes are red. (same)
Gyarados- Just like in the older games, he's red. (same)
Ludicolo- Hands are dark blue. (completely gold)
Seviper- Red slashes are purple. Yellow areas are neon green. (same)
Tropius- Colors are just lighter, not different. (same, but with slight greenish tinge)
Gardevoir- Green areas are purple. Eyes are blue. (same)