changing RGB values at runtime

[uprize]

Is it possible to change the RGB values at runtime?
I can use the Replace Colour (GetRGB) function but it only works when the frame loads.
Is there a shader pack that would do it? I would prefer to use MMF2's inbuilt RGB replacer if possible

[Looki]

There is going to be a palette shader in Sphax' next shader pack which is able to change colors in palette A to the equivalent colors in palette B.