Media Encoder rendering the videos with a whiter opacity

I'm just trying to render an animation, and the first rendering file from after effects is in correct colours, but when I upload that onto Media Encoder to compress it comes up completely different. 

This is what it looks like after rendering on After Effects.

And this is what it looks like when I upload it to Media Encoder

I've rendered many things the same way and never had this problem, if anything the problem was the images were coming out slightly darker.