I’m adding watercolours to my gouache! It’s usually the other way around… I’ve decided to try underpainting in watercolour since I like to work wet in wet for those first layers anyway. It would be interesting to see how much of the underpainting shows through.
These are all Daniel Smith watercolours:

Hanza Yellow Light, New Gamboge, Quinacridone Rose, Pyrrole Scarlet, Phthalo Blue, Ultramarine Blue, Burnt Sienna, Yellow Ochre, Pyrrole Orange, Sap Green, Carbazole Violet, Sepia, Jane’s Grey, Moonglow, and Phthalo Blue Turquoise.