back to your first sprite...
firstly, you segmented his muscles way too much, your sprite is how somebody would look without any skin. the arms were much to large and the legs were much to short, basically everything is extremely disproportional. i suggest you look at some tutorials on body proportions, things dont have to be perfect but they definitely need to be somewhat believable.
your colors are alright, they do lack some contrast but theyre pretty much ok. you do have way too many colors though, many are extremely unnecesary.
i made an edit, more like a total redux of your sprite. i lowered the color count a bunch and tried to fix the most glaring anatomy problems. im no anatomy expert but i did as much as my knowledge can take me. i found that the others edits were too unrefined and felt that it would benifit you much more if you had a very clean edit to go by:
