While this final version looks clean and polished, it did take me several days to get it right. I had the idea for the layout early on but I struggled with the choice of colour. I needed two colours, one for each step in the Sankey diagram. I tried dozens of variations, many of which looked terrible. I had a breakthrough when I showed this to the head of design at work (thanks Mike!). He suggested I use analogous colours that do not both scream for attention. That was exactly what I needed! Two colours that were different enough to be seen as separate but similar enough to create a harmonious ensemble. To see the different colour iterations of this project, you can read this blog post.