My godness people, thank God you have an installer on the boards....
You have 3 options.
1. Easyest way would be to give toyota your VIN and they will give you the unlock code (assuming you have the radio that came with your car).
2. Buy the toyota wiring harness for your car from any stereo shop and take the radio out and plug in the harness, the harness is colour coated for the speakers, ground, accessory, constant. Test the wires with any battery and if you hear a "pop" then your speakers work. (White=LF / Gray=RF / Green=LR / purple=RR)
3. if all else fails then cut the plug off and test this out...
Right Front Speaker (+) Green Gray
Left Front Speaker (+) Pink White
+12 Volt Ignition Wire Gray Red
+12 Volt Battery Wire Blue w/ Yellow Stripe Yellow
Right Front Speaker (-) Blue Gray w/ Black Stripe
Left Front Speaker (-) Purple White w/ Black Stripe
Ground Wire Black Black
Power Antenna Wire 1 Blue (join wires 1 & 2
Power Antenna Wire 2 together to this blue wire)
Do Not Use
Right Rear Speaker (+) Red Purple
Left Rear Speaker (+) Black Green
Right Rear Speaker (-) White Purple w/ Black Stripe
Left Rear Speaker (-) Yellow Green w/ Black Stripe
lmk if any of this helps