The many squaryliums of organic class have received a great deal of attention in recent years due to the potential applications of these materials in many fields such as electrophotographic processes, photovoltaic cells and in diode-laser optical storage recording system. Therefore, by suitable choice of terminal amino residues in the 1,3-squaryliums it is possible to displace the absorption band into the near-infrared regions. In this section, the visible absorption properties of the heterocyclic squaryliums were studied and their colour change phenomena were considered. As a these results it was designed that heterocyclic squarylium dyes could be probably suitable indicators for both titrimetric and colourimetric purposes. Interestingly, Some squarylium dyes are used for semi-permanent hair dyes due to low molecule weight, soluble in water and high affinity on hair polar structure.