Two-way (wavelength X intensity) repeated measures (RM) ANOVAs were performed to evaluate mean value differences for all sleep parameters. Three-way (wavelength x intensity X time) RM ANOVAs were performed to evaluate mean value differences in melatonin and temperature indices. Post-hoc Tukey tests were performed for significant ANOVAs. Two-tailed p-values below 0.05 were considered significant. Statistical analyses were preformed using SPSS, version 20 (SPSS Inc., Chicago, IL, USA).