And what about other technical issues, like exposure? 😉 Or chromatic aberration?
I've checked the histograms, they are all OK, but still, I think that the pictures are too dark. Chromatic aberration is highly visible, however.
I think you could adjust the exposure a bit - lighten it up, and adjust the white balance.
You should also try to reduce the green and purple fringing in the water droplets. They are quite visible!