The original colour palette (below) seemed a bit too messy and overpopulated with colour so I've tried experimenting a bit further with fewer more selective colours.
I tried out a completely new palette with new colours selections from the painting itself and not the old palette. It doesn't seem to be working too well however.
So I went back to the old palette and sampled colours from it and applied it to a more minimal version. It seems to be a lot more controlled in terms of quantity and consistency.