I've been over this a couple times on [stella]; no one can agree on "proper" RGB values for the 128 Atari 2600 colors; everybody has different ideas and different equations, and everybody claims everybody else is doing it wrong. (see
Yes, it would probably be a good idea for emulators to allow some kind of user control over the colours. But it might be better, if things were a little easier than with the formula in your web form. Could you come up with a formula that uses all the inputs that you can control on a normal NTSC TV with values from 0% to 100%? That would be really helpful.
Ciao, Eckhard Stolberg