WordPress Version: 4.3
/**
* Sanitizes a hex color.
*
* Returns either '', a 3 or 6 digit hex color (with #), or nothing.
* For sanitizing values without a #, see sanitize_hex_color_no_hash().
*
* @since 3.4.0
*
* @param string $color
* @return string|void
*/
function sanitize_hex_color($color)
{
if ('' === $color) {
return '';
}
// 3 or 6 hex digits, or the empty string.
if (preg_match('|^#([A-Fa-f0-9]{3}){1,2}$|', $color)) {
return $color;
}
}