very very good indeed!
i think that you should darken the lineart in the middle first, because the overall picture is dark and you need some balance..
the colours in the picture should almost always be lighter than the lineart (except in certain occasions)
your light source is also a bit undefined..
for example on one leg.. the light is coming from the left, and on the other, the light is shining from the right..
so it's a bit confusing there..
there should always be a more dominant light force.. it gives more of an impact with the picture and gives of a sense of balance
(ex, equal amout of light, and equal amount of dark)
i love the use of colour though :3 and the highlights are magnificent
the compostition is great and the idea is great aswell!!
keep up the awesome work!!
and i hope i didn't insult you,
i'm just trying to offer advice
:3 thanks for listening and i hope to see more art from you in the future!!
~kura