I need to know how to install an after market head unit in my 2000 Toyota Celica?

The stock headunit had the hook up with 14 wires, my aftermarket has 12. I read online that my car has a built in amplifier which i need to bypass because the aftermarket is enough to push the stock speakers. starting from the top left (looking down at the wires on the stock cord are as follows



thick violet

white (maybe yellow?)

red

brown

blank

blank

blank

red %26amp; gray dots

green %26amp; gray dots

blue w/yellow stripes %26amp; grey dots



now from bottom left

brown %26amp; gray dots

gold

blue

green

black

blank

blank

blank

white w/green stripes %26amp; grey dots





On my aftermarket it has these (not in order)

red

black

blue

yellow



then speaker wires

so ive color coded the blue, red, yellow, and black wires and turned the car on but head unit won't turn on. im assuming im gettin cords mixed up considering some are for the stock amp so i need a wiring diagram for my car.I need to know how to install an after market head unit in my 2000 Toyota Celica?
Your car manual should have a wiring diagram in it. They make the colors so close though haha.