  We derive the moment generating function for photon emissions from a single
molecule driven by laser excitation. The frequencies of the fluoresced photons
are explicitly considered. Calculations are performed for the case of a two
level dye molecule, showing that measured photon statistics will display a
strong and non-intuitive dependence on detector bandwidth. Moreover, it is
demonstrated that the anti-bunching phenomenon, associated with negative values
of Mandel's Q-parameter, results from correlations between photons with well
separated frequencies.
