Euphorbia Barrel Hybrid Cactus Study

I decided to do something different. I like this an Euphorbia Barrel Hybrid cactus because it is kind of crazily energetic for a plant that does not move , and yet its swirling structures suggests an attitude of motion. It is also graphic and textural. I think the dusty kind of surface texture will be a challenge. So far I have a loose value study and a color sampling. I am playing around the with idea of the first wash being kind of granular by using some cerulean and cobalt blue. I am working with some Kremer pigments which granulate nicely, but tend towards opacity and Daniel Smith Watercolors. I find have to do a lot of color samples. I need to see the colors next to each other, so I can appreciate the nuances of each color. This preliminary work has become a ritual of discovery that I have come to enjoy as much as the actual final painting of the subject. I always tell my students that watercolor is a "performance medium" and right now I am "rehearsing."