Zippo lighter fluid is the best, but not everyone has some sitting around. But - the next best things to remove sticker goo is something EVERYONE has in their garage.... WD-40.
Goof-Off will work on metal, but should NEVER be used on plastic. It will melt it! (Found out the hard way...)
I won't say for sure, when I was younger I used to take stickers off toys all the time with lighter fluid and I don't ever remember it bleaching the plastics...after all, color is all the way thru plastic, not a skin like paint.
Ive been using Goof Off but it seems to be taking a long time and its not getting it all off. I wonder if I can use a scotch bright with it and if that will help or if it will scratch it all up.
Acetone with a rag and wear rubber or latex gloves because it will pull all of the oil out of your skin, but works great and wont hurt the plastics, you can get it at a hardware store or automotive store it's about 7.00 for a quart