(Author here) I cheated: to prevent that steady state (since it's ugly), I have 3 dye injectors strategically placed, causing certain areas to get redder, green

(Author here) I cheated: to prevent that steady state (since it's ugly), I have 3 dye injectors strategically placed, causing certain areas to get redder, greener, and bluer over time. Without that, yes, it turns into a muddy grey.