I was embarrassed to post this before but I figured I need help.
I’m trying to include cartoon outlines like the one used in the Stylzed demo, but when I do, the lines show up but the entire level looks brown.
I made a post process material and attached it to the post process volume. I also played around with the “before tonemapper” settings and I’m still getting this.
I can’t tell you why it’s brown… that I don’t know. Now, just before the final output on my outlines post-process material, I multiply the outlines by the “Scene Color”, if I don’t all I get is black.
Try multiplying the Scene Color by your outlines.
Tried it and still not getting anything. 
I also went on to try this guy’s shader but I’m still not getting the right effect.
Ha, I finally figured it out.
It was the blend weight. By default, Epic included it in their material, but they also made an instance of it that they changed later.
When you try to use the material by default, it wont recognize the blend weight in the post process volume (thus why it looks brown). You have to change it to zero in the material and then it works.
There’s still more I want to do, but I’m glad I finally have lines now.