Thats not going to happen.
If the colors werent there in the first place, they arent going to be revealed.

Spic and span and hot water works as well as anything in an ultrasonic cleaner for firearms actions. Simple Green and water works too.

My ultrasonic cleaner has 8 minute cycles, and I routinely do it four or five times until the water comes out clear. I change the water after each couple cycles.
Unbelievable what comes off.

But, it will be so clean when you get done you absolutely must relubricate it, for fear of rusting. And the steel will be quite hot if you use near boiling water.

Out there doing it best I can.