I'm missing something. Do you mean html color palettes?
An html color is represented either as a hex value of 00->FF for three base color colors:
where 00 is absence of that color and FF is max brightness of that color, e.g.,
black: 000000 or rgb(00,00,00), red: ff0000 rgb(FF, 00, 00)
Usually palletes are displayed with way fewer elements, and they are presented as a sort matrix.
You need an array of 16 million to handle every color, which is not usually a practical approach.
That said what are you trying to do? Exactly? As a guess: Are looking for SDL perl apps?
Simple DirectMedia Layer google for SDL glue.