红颜虽美却是祸水蓝颜甚好奈何有毒
[hóng yán suī mĕi què shì huò shuĭ lán yán shèn hăo nài hé yŏu dú]
The phrase reflects an appreciation of good looks (red faces refer to beautiful women, blue to handsome men) combined with the warning that they might bring trouble - similar to the old saying about vanity being perilous.