I found several more in the series of spot paintings I made back in 2011. These two are my favourites. They are based on mixing watercolour pigment washes in several strengths and then dropping, using a pipette, onto blotting paper in sequences. The colours were not mixed in the pots, they simply merged a little once dropped onto the paper.
Sally Wakelin - Studies in Creativity 
Enjoying these Sally, especially the optical colour-spread that takes place in the first one with the external yellow circles. Lovely.
Ah thanks Andy, I made a considerable number of these paintings a few years ago, mostly just using indian yellow, alizarin crimson and cerulean blue but have tried other pigments too. There are great variations in the way the different pigments leach out as they dry, some mix, some stay on the surface.
I simply LOVE these, Sally. They are fascinating to me.
Ooh thanks Anita, I’ll find some more photos of the others tomorrow and post some more.