protected function shortenHex($content)
{
$content = preg_replace('/(?<=[: ])#([0-9a-z])\\1([0-9a-z])\\2([0-9a-z])\\3(?=[; }])/i', '#$1$2$3', $content);
// we can shorten some even more by replacing them with their color name
$colors = array('#F0FFFF' => 'azure', '#F5F5DC' => 'beige', '#A52A2A' => 'brown', '#FF7F50' => 'coral', '#FFD700' => 'gold', '#808080' => 'gray', '#008000' => 'green', '#4B0082' => 'indigo', '#FFFFF0' => 'ivory', '#F0E68C' => 'khaki', '#FAF0E6' => 'linen', '#800000' => 'maroon', '#000080' => 'navy', '#808000' => 'olive', '#CD853F' => 'peru', '#FFC0CB' => 'pink', '#DDA0DD' => 'plum', '#800080' => 'purple', '#F00' => 'red', '#FA8072' => 'salmon', '#A0522D' => 'sienna', '#C0C0C0' => 'silver', '#FFFAFA' => 'snow', '#D2B48C' => 'tan', '#FF6347' => 'tomato', '#EE82EE' => 'violet', '#F5DEB3' => 'wheat');
return preg_replace_callback('/(?<=[: ])(' . implode(array_keys($colors), '|') . ')(?=[; }])/i', function ($match) use($colors) {
return $colors[strtoupper($match[0])];
}, $content);
}