This method is used to set a color at a specific color ID inside the color cycle.
The following colors syntaxes are understood by this method:
"#ffff00" hexadecimal format (HTML style), with and without #.
"#08ffff00" hexadecimal format (HTML style) with alpha channel (08), with and without #.
array with 'r','g','b' and (optionally) 'a' keys, using int values.