A Generative Approach to Simulating Watercolor Paints
Tyler Hobbs is a generative artist, using Quil to create images. Tyler’s write-up of this watercolor-paint-generation is effective both as a walkthrough of the artistic process and as a handy approach that you can borrow ideas from.
The basic idea is to take an irregular shape and composite a lot of slightly-varying nearly-transparent copies in a stack. There’s some nuances to Tyler’s approach, which results in the gorgeous look you can see above.