Since it's showing a probability density, wouldn't it make most sense to just use a grayscale in this case? As the probability density approaches zero the visual would disappear as well. This is more intuitive, as the probability is zero off the edge of the graph/page

I think you only need this color vomit if you have a change between two states, or you have multiple intermediary states and want some visual "clustering".

You can actually see the problem very clearly b/c it ends up having a weird dark-blue to white cut is some of the plots.