I have read about pigments available in the past. What did Celtic artists work with? In spirit, I tried working with earth colors--Burnt Sienna, Yellow Ochre, Burnt Umber. But, I did use dabs of Winsor Violet and Cerulean Blue. Today I was reading about limited palettes, in particular the Velasquez, so I tried to make my purple with Burnt Sienna and Ultramarine Blue but only got to a nice brown. I've not done much with watercolor so there's plenty to learn about color mixing. Where I had fun and surprise was in simply diluting a paint. I found wonderful colors trapped within a dark pigment.