With a fully worked out underpainting in place, the color layer usually goes quite smoothly. Often it’s simply a matter of glazing (very thin layers of transparent paint) with the local color and then adjusting details. This was the case with the pomegranate, where I glazed the shadows with a dark transparent crimson. I then built up the lighter areas with more opaque reds to give a fuller sense of body.
Incidentally, the background is a glaze of Ultramarine Blue over Van Dyke Brown. This gives a greater sense of depth, and something of an elusive quality that a straight application of black would not have.
That’s one of the subtleties of seeing a painting in person that’s often lost in photographing it.