I have a pioneer DEH 525-W car sterio harness and colors do not match to that of the Saturn L2 1999. How do I connect this car sterio?

Just go to Best Buy and buy the Saturn L2 1999 Harness . then it will match. Harness cost like 20 bucks.
1st STEP
Things to get from BEST BUYor RADIO SHACK.
1. Black electrical tape
2. (Optional) for quality connection Solder & Solder gun
3. GM (General Motors) Antenna Adapters
4. GM 1999 Car Harness
5. GM Saturn L2 1999 Car Kit

STEP 2 = Match the colors of the car harness you just bought to the harness of the radio (DONT PLUG IT INTO THE CAR YET CAUSE YOU MAY SHORT OUT THE POWER WIRE TO GROUND) twist the same color wires together and then tape them so it wont be exposed to get shorted out and damage your radio or blow fuses in the car.

STEP 3= plug in the complete harness to the radio and the car and also plug in the Antenna adapter to the small antenna jack of the car that converts it to a larger jack so you can plug it in the back of the new pioneer radio that has a larger antenna hole. Now test the radio it should work unless you had blown your radio fuse in the car already which is easy to replace.

STEP 4 Unplug everything from the radio and install your CAR KIT. Then slide your radio sleeve in the rectangular hole all the way flush and use a flat head screw driver and bend the tabs of the sleeve(Radio Cage) so that the sleeve wont move.

STEP 5 make sure your harness & antenna is sticking out of the sleeve so you dont have to fish it out later when you have finished mounting the car kit to your car. Put your car dash back together and you will see only a rectangular hole with a harness and antenna adapter sticking out only.

STEP 6 plug in the harness and antenna back into the radio and slide it in halfway only and test the radio again making sure everything works. If it does then move it all the way in till it locks into place. last snap in the face trim ring into place to cover the silver cage lining.

THERE YOU ARE FINISHED