Automatically change text color to assure readability

Question

Users can set the background-color of a button through a textbox that accept RGB hexadecimal notation: ff00ff, ccaa22, etc. So I need to set the te

Answer 1

var getContrastYIQ = function(color) {
  var hex = '#';
  var r, g, b;
  if (color.indexOf(hex) > -1) {
    r = parseInt(color.substr(1, 2), 16);
    g = parseInt(color.substr(3, 2), 16);
    b = parseInt(color.substr(5, 2), 16);
  } else {
    color = color.match(/\d+/g);
    r = color[0];
    g = color[1];
    b = color[2];
  }

  var yiq = ((r * 299) + (g * 587) + (b * 114)) / 1000;
  return (yiq >= 128) ? 'black' : 'white';
}

Thanks for the post ZetCoby! Had to adjust your "color.substr(" array position to account for the initial '#'; then it worked great! you could also use a color.replace('#',''); within the if block...