Yes, its extremely important to have this color Twin mentioned, #a8a088, for portraits as the first color in the portrait's palette. Otherwise you will get the dreaded white/light blue line appearing in game. You have to have it at 16 colors, but don't be lazy now, just because it auto adjusts and makes usually the darker colors look weird, like in yours the darkest color is like dark red (not talking about the black background), you should just change it manually to something you're happy with. Always always always work with 16 colors and it is very wise to choose your palette before you begin, that's what I do and I believe almost all spriters on here do like Twin, Kage, etc.