shadeColor(color, offset)color(string): the full string of the color to shade (can include or skip the leading#). Must be a 6 character color (TODO: allow 3 character colors)offset(integer): how much to shade the color. Positive numbers will make it lighter, while negative numbers will make it darker. 0 will leave it as is. The default is-1which will make it "one shade" darker.
