Models for the scaling of the SNIa rate per unit mass of formed stars with the U − J colour of the parent galaxy, for different assumptions on the SFH and the DTD. Vertical panels share the SFH law as labelled on top, and horizontal panels share the adopted DTD, which are labelled in the left panels together with adopted values for k_Ia in . The symbols and colour encoding is the same as in Fig. 4, with star forming and passive models shown as filled and empty symbols respectively. In the right panel relative to the DDC DTD, we show the evolutionary line of a model which undergoes quenching at z = 0.75 when the universe was ∼7 Gyr old. In the same panel the vertical dashed line connects models with the same colour, but different SNIa rates (see text).