100 Snow Leopard Tips, Tricks, and Features | Mac|Life
http://www.maclife.com/article/feature/100_snow_leopard_tips_tricks_and_features
Panic Blog » Saving Icons for Snow Leopard
http://www.panic.com/blog/2010/06/saving-icons-for-snow-leopard/

Workaround for the fact that Icon composer on 10.6 makes your icons look washed out

You may have noticed: icons made in Mac OS X 10.6 are often washed-out/lighter