I think it looks great. Without the experience at this I can't give any real critical appraisal, but it actually looks painted to me.
That's actually very nicely done. You should be very proud.
I personally would have taken some even darker blues for the costume and shaded in a little more detail in places (creases in the hand, swell of the breast) but I'm one of those people that uses six different shades of the same colors just to make shadows...
Thanks for the advice, I may go back and touch it up. 
I like the painted look.
POINTER: Make sure to choose a singular lightsource (or make it obvious at which direction multi light sources are coming from).
<----used to not understand light source XD so I feel ya 
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Yeah, I have a real problem with that! :3 Thanks for the advice though!
TRUST ME, when Bob was teaching me light source, I was like, "HUH???" LOL I had never thought about it in ANY Of my stuff, coloring or otherwise.
But you'd be surprised, how even a TOUCH of it can make a piece look 1209481093570192480198 times better
If you need any specific pointers on thatleme know babycakes!
<3
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I think the hand is quite good. You might want to smooth the darker shadow that forms her chin, the uneven edge makes it look like she's older than she should be... virtual chin lift!
As for the hair, check these out...
heise - just masterful...
getty - good example of the lighting source Sorah was talking about...
If it was me I would pick a different shadow color for either your hair or white parts of the costume. Even though "we" know it's supposed to be white, white reflects the light around it and picks up colors, which is why many artists just use lightest to lightest of their colors to depict white. That way your white can be true white and really pale purple, or pink, or yellow, etc...
Or you can use 2 different light greys and white also.
LJ
Lesson I was reminded of:
While I already functioned this way, Bob always makes sure to point it out DESPITE the fact that I automatically do it...
As Lady above was saying, what many colorists fail to remember that white is a color and that you ALWAYS want to be sure to make your figure 'pop' (unless intentionally obscuring, but in most cases you are trying to make 'em pop).
So in that...
Just like blacks, whites have a varying degree of 'color' that they take on. You almost always want to avoid GRAY of ANY sort. Meaning? If on your color palette you are not teetering on the edge of color - try again!
Remember, you are trying to add depth and texture to your character, you are falsely tricking the eyes into thinking something is 'real' when it is in fact 2-D.
Best bet: (and I'm ALWAYS doing this cause I'm STILL learning with colors) - whenever you are on the phone, having a smoke, something where you have 3-5 solid minutes of mind wandering, go outside, or pay attention to the way shadows bounce, colors take on different shades, all that jazz. Observation is an amazing learning tool (oh and make sure to take into mind the textures of all surfaces - metals vs. cloth).
If you really wanna get some coloring tips, I can direct you to my pseudo coloring teacher's forums
EDIT: To recap, I was talking about the 'making your figure pop' thing - ALWAYS REMEMBER TO CREATE CONTRAST! So unless you are INTETIONALLY obscuring something, you never really wanna put a white caped toonagainst a white sky, kinda thing.
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Makes sense and thanks for those links LJ!
While I'm certainly no artist, and not really an expert on anything having to do with art, I couldn't help the feeling that the outline on the hair was a little too thick. The black outline around the hair just stood out to me for some reason and just didn't seem right.
But, take that for what it's worth. Like I said, I probably don't know what I'm talking about. hehe
your = Belonging to you.
you're = Contraction meaning "You are."
Ur = The name of an ancient Mesopotamian city.
ur = This is not a word.
I colored a pic of Larissa that Alex did. Let me know what you think, I have thick skin and my feelings won't be hurt!