Illustration of the PSD for two different rest-frame wavelengths (2700 and 5200 Å), for a fixed black hole mass and Eddington ratio. It shows that longer rest-frame wavelengths correspond to lower normalization in the power spectrum. The break frequency (f_b) varies inversely with λ_RF and predicts that the bending will occur at higher frequencies for bluer wavelengths. The predicted values of f_b for 2700 and 5200 Å are shown with a blue and red star, respectively. However, the observed variance trends present a steeper decrease at 5200 Å than predicted, as is depicted by the dashed line in the figure, suggesting that the high-frequency slope of the PSD is wavelength-dependent.