RGB is to less

Can you even differentiate between these 2 colors? For a case like this you might be wasting time but check this: http://stackoverflow.com/questions/726549/algorithm-for-additive-color-mixing-for-rgb-values , but taking the ceiling of the average for the red component will give you 101

There are an infinite number of colors between them; however, they are not displayable due to the limits of programming are concerned, and two colors that close are virtually identical (or undistinguishable) and for programming purposes are not needed. I think what you want is to do something like the SmoothMover class does for movement. That is, use 'double' values to track each color part, adding and subtracting fractional amounts to them, but using their converted 'int' values to update the displayed color.

@davmac: I need it for my Mandelbrot-Set scenario. I want tthe colours being smooth like in the screenshots in the wikipedia article: http://commons.wikimedia.org/wiki/File:Big_Mandelbrot_set.jpg @ danpost: Yes you are right by thinking what I mean. Actually I am doing it kind of this way so far. I have a ColorSpectrum class, which has the static method for getting every color of the RGB spectrum with a constant alpha of 255. So I have 1530 colours. The parpameter is an integer: Replacing the integer only by a double value is useless. Thanks for help so far.

@Kartoffelbrot Making the color objects more precise won't help: as danpost said you can't see it. And to get smooth colors, you should use the technique called Continuous coloring, which still uses the normal colors but interpolates the colors between 2 values which are far away, not closely :)

Your monitor can only display 24-bit colour at the most (8 bits Red, Green, Blue). It's unlikely that you'd be able to tell the visual difference between the two colours (a,b) that you describe above.