I just did my rear diff last weekend. The color of mine was the same color. My truck had 21k miles when I did mine. And I never been off road or been in an area with high water. Take it to the dealer and see if it's bad. If you do change the fluid the longest part is going to be cleaning both contact surfaces so you get a good seal. Good luck with what ever you do and let us know how it turns out. Here's my rear diff removed and some fluid to compare
It too.

 

so you say the color of the front diff fluid was the same as the rear? alright ill be sure and let yall know what i find out

 

Didn't do the front but the front diff fluid is just a different viscosity from what I know of.

 

got it back from the stealership last week and they did the standard fluid change. at first they said they would just suck it out with a pump, but i requested that they drop the cover. so hopefully they did everything right. it seems to be fine now. cost about $120