It's slightly more than just frequency. Magenta colours don't show up in the spectrum for instance. But yeah it's basically just hue, saturation and brightness

It's slightly more than just frequency. Magenta colours don't show up in the spectrum for instance. But yeah it's basically just hue, saturation and brightness. And your choice of colourspace is more or less arbitrary although there's been quite a bit of research on what colours humans consider to be 'close' or 'equally bright' and even which combinations are 'pleasing' but that last one is hard to make precise.