arty-charty/util.js
function rgbaToHsla(h, s, l, a) {
  return [...rgbToHsl(h,s,l), a];
}
function rgbaToHsla(h, s, l, a) {
  return [...rgbToHsl(h,s,l), a];
}
function rgbaToHsla ( h , s , l , a ) { return [ ... rgbToHsl ( h , s , l ) , a ] ; }
Converts a RGBA colour to HSLA.
Converts a RGBA colour to HSLA .