1 CVI Crystal violet 1.000 2 MGR Malachite green 0.893 3 1OM 4-{bis[4-(dimethylamino)phenyl]methyl}phenol 0.862 4 6FE 4-[[4-(dimethylamino)cyclohexa-2,5-dien-1-ylidene]-(4-methoxyphenyl)methyl]-N,N-dimethyl-aniline 0.833