Yeah, I wrote a "toon" shader some time ago for v4.5 (see attached). To edit the color, change the ramp shader, and to control the line attributes, see the "extra attributes" in the channel box.
The problem with every "toon" shader I've seen (and I'm not counting plug-in renderers) is that they all do nice jobs with curved surfaces, but do poorly with straight edges. Most WILL NOT even outline a cube. Maybe use a "toon" shader for the main part of your scene, and then use the vector renderer to get your outlines, and comp it together in post.