That restricts you to 8 bits per color channel, and more importantly, to the RGB color space which is non linear. Comparing colors in RGB color space is nonsens

That restricts you to 8 bits per color channel, and more importantly, to the RGB color space which is non linear. Comparing colors in RGB color space is nonsense in the first place ('comparing' here is 'judge by human perception'). 'Comparing' colors is just not that easy; in fact, I'd argue that without (much) more definition and clarification, it's impossible to do, because it can mean different things depending on the purpose.