In the animated Teen Titans series both Raven and Jinx had a gray skin complexion instead of there usual light brown hue, is there a reason for that? I know that there were modifications made to suit a younger audience and prevent animation glitches like Gizmo not having a beard and Jinx actually having hair but why would Raven or Jinx's skin color change?

They had to make things different for kids. For example; they gave Starfire more clothing because of her... less clothing. For Raven and Jinx, I believe they wanted two gothic kind of teen girls, and to have an opposite to the colorful Starfire (figuratively and literally)

Because it's anime and anime and superheroes never mix well, in my opinion

"They had to make things different for kids. For example; they gave Starfire more clothing because of her... less clothing. For Raven and Jinx, I believe they wanted two gothic kind of teen girls, and to have an opposite to the colorful Starfire (figuratively and literally) "

The cartoon made plenty of random changes, most of which made no sense. Raven and Jinx aren't the only ones that changed looks.  Some others were altered quite a bit as well.
 
Pantha went from being a catgirl to a wrestler. I heard it was because they didn't want to use a 'furry' despite already having (Baby) Wildebeest. Not to mention they created a catgirl for the movie so there's no reason they couldn't have used a pre-existing one in the cartoon.  Wildebeest himself was also changed quite a bit. 
 
A huge change in appearance was Killer Moth. Which was actually good IMO.

cause she was deep.

" I think they did it to look more inhuman. "

It call comes down to the same question raised when people ask "why did they change x?" 
 
Because the creators thought it would be cooler.

" @Redtha: For Jinx, I don't know maybe they wanted to make her look something like goth. As for Raven, I remember reading somewhere that they did it to make her look more inhuman. "

I think its done more to be 'interesting' and sets her as non-human, off the bat, without having to go into her rather convoluted background, so that when they did get into the deal with her demonic father, the viewers would buy into it quicker, rather than scratching their heads, and thinking 'Wait a minute! I thought she was human? or if not human, some simple 'no explanation needed' alien, like starfire.' 

thats not grey

Giving her a pale and grey-ish complexion made her more of a 'teen goth' like they were going for. I liked the fact she was change in that way, her character looked more magical and cool.

Anime tend to have lots of random colors anyway, be it on the skin or the hair of characters..
So they turned her into an anime goth, you know, with blue hair and grey skin! :P

I really don't mind the gray skin. I actually think it suited Raven in the animated series. You know, there's that whole emo feel to here because she can't feel anything because then her powers go out of control... so I think the gray skin is pretty much due to her dark persona. It actually looks pretty artistic (I know, weird use of adjectives, but I used this word solely because nothing else can come to my mind right now).
Again, I don't mind the changed skin at all, because Teen Titans was one of my favorite animated series.

This it had soemthing to make her claim her own niche of the color spectrum, so she wouldnt have to share with Robin, note that none of them actually share anything in that regard, unlike say, X-Men. You could say the colors they have are all telling of their personalities, Raven is calm and depressed, fitting with the blue and grey (think of how her emotions were colored in her head).
While i believe the animators thought that Raven's skin could be explained because of her heritage, since her dad was a red skin and her mother pink, what are the odds she would get normal colored skin anways?  
Also it could be the animators perception of Goth's, but not wanting to make them bone white, settled for grey instead. 
 
Regarding the comic, the altered skin color would not work, not now at least, if it was to be, it would have needed to have been part of the NTT as well. Now it would just be seen by old time fans as more catering for the cartoon audience, which has already made of both Beastboy and Raven by pairing them together. Something that never existed before the cartoon, but then again post-ressurection Raven only acted like NTT Raven in the panel where she was about to leave teh team after they saved her from Brother Blood the first time.

I liked the gray skin goth look better than normal Raven.

@whitewing: why can't they just call the terminator instead of slade. It could be better if they had him unmask in the first place

@batmanx2005: Partly because 'Deathstroke' isn't kid-friendly and the worry that 'the Terminator' will confuse people with Arnolds robot.

They made every character in the Teen Titans animated series opposite to their comic counterpart.

If you'll notice, each Titan in the animated series had a different skin tone. It probably had layers of simple color coding with the addition of being an exaggeration that can be remembered as pale white skin (Kind of like how people remember Mr. Burn's blue hair as grey on the Simpsons).

I do mind the skin I just wish someone would just make her suffer

@batmanx2005: What?

He has posted stranger things, believe it or not.

@farkam: What!? It really is hard to believe you know...

So the girls had team Edward or other guy Who I forget the name of... Moving on... And the boys had Raven or Jinx, and got their necrophilia on... the rest is dirty sock... :1 Goodbye, Farewell, Au Revoir, Adios. We hope U enjoid THU SHOW... THANK U, MY FRIEND, We'll get U in the end.... We hope 2 C u UGENN :1

i like her Gray skin !

@super_ninja: Same!

I'm use to seeing her with gray skin

Right now, I wouldn't be opposed to her gaining a more unique skin coloration since most of her artists now a days appear to favor showing her face rather than hiding it away in the shadows of her hood. Admittedly right now she'd probably need to suffer somekind of trauma for that to happen or some weird story to be told that her normal appearance had been somekind of illusion.