What color do coumarins fluoresce?

Coumarins produce blue colored light when becoming fluoresced. Coumarins are UV-excitable, with short emission wavelengths ranging from ~350 to ~480 nm. Coumarin derivatives are also UV-excitable, and produce blue during fluorescence. The most commonly used coumarins are AMCA, 7-aminocoumarin, and 7-methoxycoumarin for creating blue fluorescent peptides. Compared to fluoresceins, cyanines, and rhodamines, coumarins create fairly bright and photostable fluorescence. This is due to their low extinction coefficients.