Abstract: Compounds useful for imparting deep maroon and rubine shades to natural and synthetic polyamide fibers of the formula: ##SPC1##In which:A and B represent phenyl rings, a --SO.sub.3 H group being attached to one of said rings, to which other non solubilizing groups selected among lower alkyl or alkoxy, NO.sub.2 and halogen may be attached;C represents a naphthyl group or a phenyl group, one or two lower alkyl or alkoxy groups being possibly attached to said phenyl ring;D represents a phenyl ring;R.sub.1 represents hydrogen or a lower alkyl radical which may be substituted by a cyano, hydroxy, acyloxy, halogeno or acyl group;R.sub.2 represents a lower alkyl radical which may be substituted by a cyano, hydroxy, acyloxy, halogeno, sulfonic acid or phenyl radical, the phenyl radical being possibly substituted by a non ionogen or ionogen solubilizing group, andR.sub.3 represents hydrogen, a halogen or a lower alkyl or alkoxy group.