Use SASS to get the contrast color based on a color's luma value (the Y in YIQ). http://en.wikipedia.org/wiki/YIQ This calculates a color that is much more readable. Read more from the W3C. http://www.w3.org/TR/AERT#color-contrast

_contrast-luma.scss

/*
 * Calculate Luma
 *
 * Luma measures a colors percieved brightness
 * by the human eye.
 * http://en.wikipedia.org/wiki/YIQ
 */

@function luma($color){

  $r: red($color);
  $g: green($color);
  $b: blue($color);
  
  @return 0.299 * $r + 0.587 * $g + 0.114 * $b;
  
}

/*
 * Contrast Color w/ Luma
 *
 * Calculate the contrast based on the luma
 * value of the color, as per W3C.
 * http://www.w3.org/TR/AERT#color-contrast
 */
@function contrast-color(
  $color,
  $dark: #000,
  $light: #fff,
  $threshold: 130
) {
  @return if(luma($color) < $threshold, $light, $dark)
}