Non Mutable variables and color calculator improvements

[aqua_scummm]

I would like to have non mutable variables, so that you can define them at the top, and use them in all your functions. That way, when youre changing values to get different results, you can just change the value at the top and not run through all the various functions


Also, it would be cool if in the color calculator, you could specify an estimate of how many iterations you will be going through, and it can tell you the amount you should change each iteration to get close to the wanted end result.