Did the background change when you hit the reset.
Try it without the # sign
Actually I found an error in my code,
To fix it for now, open core/common/pilotdata.class.php, around about line 486, theres:
sscanf($color, Config::Get('SIGNATURE_TEXT_COLOR'));
Replace it with
$txtcolor = str_replace('#', '', Config::Get('SIGNATURE_TEXT_COLOR'));
$color = sscanf($txtcolor, '%2x%2x%2x');