Above are the basic 16 colours used by the Windows Operating System (set out as B+W+greys, +primaries [RGB], +secondaries [YMC]). All browsers recognise the 16 names shown, but these are the only colours "quoteable" without confusion. The rest need hex-codes for portability.
Modern video-cards/monitors enable 16-million varieties of color, but browsers still only use about 240-max-colour palettes. These can be 240 varieties of reds, or blues+creams or whatever, to a limit of 240 max. colours in any one image. But that allows all the variety you'll ever really need, as can be seen from the shade-chart of 195 colours below.
The shade-chart itself was programmed from scratch by me to show both a
balanced variety of colours and the hexadecimal RGB coding of each
colour. The dump-function was modified from an example about arrays in a