THe player sprite has to stick out, but not as much as the enemies or environments - especially if you are eiming for something similar like in "a bastard's tale" it's be goo dif the contrast would be considered really well. Usually you need greens, grays and browns for the environment (if it's a basic european environment), for the enemies red is best because red just captures your sight. Therefore you either have purple, orange or blue for the main character.
The biggest issue I can see with all of your art is the proportion of lower body length to upper body lewngth. Usually the upper body is just a tad longer than the lower body (1/3 head or half a cranial mass for most people if we are speaking about average proportions)
In all sprites you have the lower body length is 1/3 while the upper body length make 2/3ds - you just draw the legs considerable to short and because the torso is too long the arms also look to short as additional effect.
For a sprite of that size it's just a difference of 2-3 pixels, but it really makes a huge difference.
It's a very common beginner mistake if it comes to draw human figures that arms and/or legs are to short.
It can work with some big headed chibi pixel art sprites.
However since it seems you want to have a certain amount of realism, I'd suggest that you work on that and do it right from the beginning.
Here is a little chart which should explain everything visually:
