Complement function?

[srcspider]

ie. given a background color what's the appropriate foreground color and vise versa

[harthur]

Do you mean whether to use black or white text over a background color? Or are you thinking of something else?

[srcspider]

More like shades of gray, but black or white or a function that takes 3 colors, the background and two possible foreground colors (say #222 and #eee) and gives you the most appropriate of the two would also work.

[harthur]

Seems like you could do something outside the library:

function betterColor(bg, color1, color2) {
  if (bg.contrast(color1) > bg.contrast(color2)) {
    return color1;
  }
  return color2;
}

[srcspider]

Ah! Thanks.