Selection function of the ZTF SN Ia DR2 sample and its effect on the color distribution. Top: Probability that a SN Ia spectrum is acquired and leads to a classification as a function of SN Ia peak magnitude. The model is the survival sigmoid function 1 − 𝒮(18.8, 4.5). Bottom: Distribution of the ZTF SN Ia DR2 color (black) compared to the expected parent population (orange) and simulation predictions (1 and 2σ, light blue) for various redshift ranges (see legend).