I like the way the newer version is colored, I think it is more vibrant and stands out more... but at the same time if you're trying to bring the tree to life, why have the red and brown leaves which symbolize wilting?
I think the trunk needs to be redone (I'll try and edit it to show what I mean,) because the sheer amount of bumps and lines makes it seem more like a group of vines that are growing together.
You might also want to remember that for shading there are sometimes tints and shades of purples on the underside of the tree to accentuate the shading while still having color instead of being dull.
You can see what I mean from the bottom left example you posted. The light source is from the upper left, so the purple shading is on the lower right
One last thing, is there a specific light source for the tree? Because it seems that it might just be from straight up, which means the trunk shouldn't have as many highlights as it does.
All in all, I think it'd work great as an artistic piece as-is, but may need some refining otherwise.