In this research, a series of triarylmethane dyes was synthesized by a condensation reaction of N,N-diethylaniline with various aromatic aldehydes. Effects of the aromatic aldehyde on the dye formation, solubility and photophysical behavior of the triarylmethane compounds were investigated. Most of triarylmethane dyes have good solubility property in organic solvent. The resulting triarylmethane dyes had green color. The selected triarylmethane dye 10 exhibited high solubility in gasoline and common organic solvents. The triarylmethane dye 10 at a concentration of 12,000 ppm was found to be stable in gasoline for at least 3 months. A series of formazan dyes was synthesized by a condensation reaction of cardanol with phenylhydrazine compounds, then coupling these products with diazonium salts of various aromatic amines. Effect of the solubility and photophysical behavior of the formazan compounds were investigated. In most cases, cardanol in the dye molecules was proved to be advantageous in giving dyes with satisfactory solubility in fuel. The resulting formazan dyes had yellow and orange color.