About your colours mike theres no real 'place' to learn good colour theory, you should really focus on contrast, hue and saturation and mostly what colours work well together. Make sure your colours range from light to dark evenly enough to let your shading shape your character the way you want remembering darker shades can push parts back and light shade can pull it closer to our eyes.
Also be aware of how saturated your colours are, don't be afraid to use bold colours but the more saturated the more our eyes attract so use duller colours for things you don't want so much attention for example, and it can also be great for adding subtle details that just add to the image as a whole. Your newest update on that girl in stockings shows this, her skin works much nicer now imo.
This is pixel art so in tradition it's always best to make full use of your palette to just always be on the look out for how you can use a colour elsewhere, if a shade for one part is so close to a shade of somewhere else, theres nothing stopping you trying to make a mix of the two and sharing the one colour. But doing that too much can make everything a bit samely, the hair of the sword weilder is blue like his jeans, a slight variation could make it much more interesting.
Just know you can always tweak any colour, make it darker, lighter, more red, more blue, whatever..
Don't worry about taking away that sword, you may want to focus on the character without having to worry about the whereabouts of a handheld object. Don't let the sword define the characters posture too much.
I wouldn't knock yourself so much you're really pretty good at this mike.
