Abstract We systematically synthesized bioluminogenic substrates bearing an amino group on benzothiazole, quinoline, naphthalene, and coumarin scaffolds. They emit bioluminescence in various colors: red, orange, yellow, and green. An amino-substituted coumarylluciferin derivative, coumarylaminoluciferin (CAL), showed the shortest bioluminescence wavelength among substrates reported so far. Further, the fluorescence ...