Hello! Edit for you!

Ignore the pixel tech in that, I was just dabbing madly with some new colors. Focus more on what I did with the colors/form. I added two colors to the tree, and shifted the highlights up to yellow and gave it fuller greens. You can keep the purple, that's actually a very good thing to have, I may have gotten rid of too much of it, but you shouldn't hide so much of it with green.
Might not be your intended style, but I outlined it according to the lightsource with black on the part in shadow. Also chunkified the bottom of the tree to try to get some more shape in there deviating from the cone geometry.
The water edit isn't very noticeable, but by making that one tone a bit bluer, it helps get rid of the "lines on top of a solid color" feeling that pixel water sometimes suffers from.