I will try to be fair about this. I understand you tried to do this well and I can appreciate your effort.
There is no way I could do something like this. But on the other hand, criticism is necessary in order to understand one's mistakes and to improve. So, do not take it personally, take it as an advice and an opportunity to improve.
I think colors are somehow wrong and his skin is somewhat weird.
I couldn't find a good official manga colour of Sasuke for the correct pallet. So I made a choice to use the colour of a different fan art as opposed to the Anime.
This picture the way it is colored and the way colors are used does not give you a feeling of either Anime or Manga. It feels like a fanart, which it is in a way.
It's not really meant to imitate the Manga or Anime in the style re-guard.
Your choice about making Rinnegan is yours. But I believe it would've been better red.
It was a hard choice when there was two contradicting coloured images, both labelled "official". I can always change it. But, until the anime we won't know the colours, and even then they may not be "correct".
I think you shuld have used shading more similar to the one in Manga.
So you prefer "solid" shading? That's cool, I was tossing up which style of shading to use, and chose this one for how smooth it is.
And the biggest problem I have with your picture is that it does not convey the feeling of darkness, which was present in the Manga.
I agree, perhaps if I had merely removed the white from the Manga image and coloured it keeping all of the original line instead of just making my own line art and colouring it.
There are also good things about this picture, other than your choice of colors, the way you colored it was really good.
That said, I am not an expert. This is just my opinion. I hope you do not mind criticism. And do not let criticism decrease your confidence.
This was a great try. And I believe you can greatly improve it or any other picture. Keep doing it and well done.