It's a firefox extension called 'Color Inspector 3D', which lets you analyze the colors of any image you can right-click on.

 Whoa what program is this? Thanks for the crit too.

very cute work! ^^

Quick crit -- you have 3 brownish colors that are very similar, you could merge them into one - see http://imgur.com/Jmdrw

 Thanks so much! I never thought of breaking up the black outlines but it really does make a difference. AA really does make parts much more harmonious. Some trouble I had was when to AA, I just added a pixel or two for outline shifts. I was a bit worried that the ball might look too bally and look odd. For the face I'm not sure as to what parts I could shade, I tried some depressions along her eyes but it didn't turn out so well.

Looks really cute. I like this a lot. I think the anti aliasing could be a little smoother in some places. I'm not really saying it needs to be, but if you want it to be then there's ways to do it. You're basically not going to get it smooth on an exterior outline without certain techniques that are more situational, but on internal lines you can break up the dark core of the line as well as adding intermediate pixels into the row/column shifts of the line.

Here's an example of what I mean- aa line
The left line has no AA. The upper part of the middle line has an intermediate color added in places where the line shifts over by a pixel. The lower part of that line has that plus another intermediate between that one and the rest of the line located at the ends of each line segment, seen in the closer version on the right. This eases the line into the AA and makes it slightly smoother overall. It's not a perfect example but it's the basic idea.

Here's the idea in action- jawline edit - zoomed in line
All I did was a tiny edit to the jawline by changing two previously black pixels to an already existing color on the palette and the line is slightly smoother. This makes her jaw a little rounder and gets rid of the jagged black pixel that was sticking into it a bit. Again, it's not a perfect job, but that's the idea I'm talking about.

A completely seperate topic, but I like that ball that some of her hair is wrapped up as because it looks very spherical. I think it'd be cool if the rest of her was a bit more 3D to match. For example the face is very flat in comparison and could have some more shading in a few spots.