The broadband phase curve and a selection of 10 spectroscopic phase curves produced for ZTF0038B (every five of the 50 evenly spaced wavelength bins). Each phase curve is fit with a second-order Fourier series with the period found from eclipse-timing analysis (Table 2). The residual columns show the phase-curve residuals as a function of phase in the center column, and a histogram of the residuals to the right. Both residual panels overlay the pipeline uncertainty (σ_pipeline; dashed) and observed scatter (σ_scatter; solid), with Δσ/σ_scatter quantifying the fractional excess scatter that is not accounted for by the pipeline. The rightmost panel indicates the wavelength dependence of Δσ/σ_scatter, and the larger markers indicate the selection of 10 spectroscopic with phase curves shown on the left.