Good stuff Rhunyc, glad to see you're still at it. I have three suggestions.
1. I'm assuming you're using the overlay method of coloring? Doing black and white tonal drawings and then putting color on top of it? I'm curious if after you do this step, if you manually select any colors? As in putting a layer of color on top that isn't set to overlay, just using your eye? I've found it helpful to do this, especially when it comes to skin tones. Overlaying color is great to get an idea of what the color will look like, but some colors can end up looking muddy so I like to go in after and manually throw some color down. If you're already doing this, ignore me.
2. I think you'd benefit from doing a few restricted palette exercises. Maybe have 3 or 4 tones and set your opacity to 100% and try to render something as best as you can. I still feel like you're over shading in some places. It creates a bit of blurriness and diminishes some of the edges. Don't be afraid of flat colors.
3. I'd like to see you color some of your pieces the way you did your Skyfall image. I've noticed in most of your pictures you tend to color everything with its associated color. Skin is fleshtone, blood is red, etc. I'm not saying go completely wild (or maybe I am) but try to experiment with more cinematic lighting. Use unexpected colors.