I agree that the sprites look good. Very ambitious project, and it really looks rather nice so far.
Minor suggestion: working with a medium shade background is generally a better choice than using white (or black). Using white or black (or any extremely saturated color) as a background can throw off your perceptions.
I see minor anatomy problems (long torso/short leg, pelvis is short) but these will be covered up by the clothes and they are minor anyway (1 pixel or less). This is good enough.
When you added AA, you added it to the outside of the figure, blending the dark outline with the white background. This works fine ... until the character is placed on a different background. For example the head in the image below. Sprites with a transparent background generally only get AA on the inside.
I don't think the hair should have a dark outline all the way around it. This contrasts too strongly with the lighter skin tones and makes it look like the figure is wearing a wig. Maybe break up the outline on the edges that will be next to skin?
I think you could improve your base sprites by adjusting your colors. Rather than fill with the lightest color of the four, fill with the second lightest color and then use the lightest color for highlights. This will let you add form to the characters and make them pop a little more. You'd have to carry this approach to the clothes as well.
Sample (I didn't get to the legs much):
Same figure, same colors, slightly different approach. This does make the figures more difficult to animate, so ignore the suggestion if you plan on doing a lot of animations.
I'm certainly not an expert, but overall I think these are well done.
Tourist