Novel triarylmethane dyes decorated with 2-thienyl, 2-thieno[3,2-b]thienyl, and 2-dithieno[3,2-b:2′,3′-d]thienyl rings as auxochromes were much more bathochromic than the known crystal violet. The hydrol precursors of these new dyes exhibited potential applications as strong and super acid pH sensors.