Rainbow Dash and Wassily Kandinsky
Wassily Kandinsky was a Russian painter who created incredibly vibrant and dynamic color compositions. You'll want to Wikipedia him. In regards to this mashup, to me his art frees color from form (I know it was really about spirituality and the Apocalypse and music as visual art), and I also think he experienced color in a fundamentally different way than the rest of us (i would not be surprised if he was a synaesthesiac). Similarly, Rainbow Dash seems to experience flying in a fundamentally different way than other flyers (how else could she perform mythic feats with little training) and she's all about freedom.
Another interesting connection involves the movement that Kandinsky was a part of - the Blue Rider. From the Wikipedia entry:
"Kandinsky wrote ... that the name is derived from Marc's enthusiasm for horses and Kandinsky's love of riders, combined with both love of the colour blue. For Kandinsky, blue is the colour of spirituality: the darker the blue, the more it awakens human desire for the eternal."
The painting in the corner is my ponification of Kandinsky's "The Blue Rider", considered his most important figurative work before he went completely abstract, and the sky panel was inspired by a fragment of his painting "Composition VII".
Painted in Photoshop
approximate time: I don't know anymore. These are just taking longer and longer.