Discoloration / yellow colloring on your MacBook
Your MacBook may look like someone has put out their cigarettes on it, or maybe someone used your MacBook with dark paint on their hands.
This is very easy to fix, however, if you don't read what I'm about to write, you will ruin your machine.
Your MacBook is made from a soft plastic. Harsh solvents can do serious damage to your machine.
Harsh chemicals include ACETONE BASED NAIL POLISH REMOVER and ISOPROPYL ALCOHOL. If you use either of these chemicals, YOU WILL RUIN YOUER MacBook. That is, the second one of these chemicals touch the surface of your computer, that surface is destroyed.
NON-ACETONE nail polish remover has kept my MacBook looking like new. It won't melt the plastic. It cleans up the dirtiness in the palm rests.
NO NOT USE ACETONE! You will ruin your computer. DO NOT USE ISOPROPYL! You will ruin your computer.
Use only NON-ACETONE based solvents. Specifically, use NON-ACETONE based nail polish remover that is BLUE or CLEAR colored. Do not use other colors, and do not use any product that does not say "Non-Acetone". It MUST be NON-ACETONE, or you will ruin you computer.
Mac OS X (10.4.6)