Cute sprite you have here. You could save some colors if you merged the midtones of the pants and used the lightest pants color for the darkest color of the skin and the darkest pants color for the hair. Or alternatively, you could use the darkest pants color for the shadows of the hair and use the midtones of the pants for the hair color.
I really like it! Lots of character and appeal - very tricky to do with so few pixels! Congratulations