Buttons::changeColor

protected function changeColor($content)
{
	$content = preg_replace(self::BUTTON_COLOR_MATCHER, 'g-btn-$1 g-btn-type-solid$2', $content);
	$content = preg_replace(self::BUTTON_COLOR_OUTLINE_MATCHER, 'g-btn-$1 g-btn-type-outline$2', $content);
	$content = preg_replace(self::BUTTON_COLOR_THEME_MATCHER, 'g-$1$2 g-btn-type-solid$3', $content);
	$content = preg_replace(self::BUTTON_COLOR_THEME_OUTLINE_MATCHER, 'g-$1$2 g-btn-type-outline$3', $content);
	return $content;
}