Hey guys! I’m trying to recreate Logan in 2.8 but
The blue node on the right is a Math Node - it can only output single channel values between 0 and 1 (opposed to three channel RGB values) so of course the result is not colored when it’s the last Node in the chain. You probably want your last Node to be a MixRGB Node - perhaps the one on the right next to the Math Node?
Also, giving the DiffuseBSDF a color won’t do anything too because as soon as you feed it into a Math Node, it’s converted to a grey value. In general, grey Sockets represent Sockets that can only take/output single channel values. Yellow ones are for color (three channel RGB values)
Anyways, the easiest way to achieve what you probably want is something like this:
But that still doesn’t explain why there’s no shadows are showing up. BTW I’m doing this in Cycles.
In Cycles Shader To RGB does not work. Just Eevee.
Emission Shaders don’t have (receive) shadows.
When you plug Colors or Float values directly into the Output Node, Blender will create an Emission Shader to show those colors (just like the Viewer node from 'Wrangler)…
well in eevee theres still color grading.
In Eevee it’s another story, but you said:
I tried redoing it in eevee, but theres still color grading.
So how do i make a shadless texture have shadows?
Shadless with shadows is something that makes little sense.
In Eevee, you can plug a simple white diffuse into the ShaderToRGB and connect the color output to a ColorRamp.
In Cycles this won’t work.
Ok, but that still doesn’t explain the color grading.
What kind of explanation are you looking for??
Stuntkoala already showed how to do it in Eevee.
If you want something even more 2d-ish, then it’s better to do it with GreasePencil.
The color looks… ew. 
EDIT: wait
