The “Absolute World Position” Material Node seems to be broken (it flickers) in the preview window of the material editor and the static mesh editor. Looking at the material in the game viewport is giving me the correct results. Just make this material and check for yourself. I think this is a pretty old bug/limitation, because it also doesn’t work with at least 4.15 and 4.16, but I still can’t find any information about it.
After creating a new material in a blank project with the Absolute World Position node, I was not able to see the flickering you describe. Can you please provide some more specific repro steps so that I can look in to this issue?
That’s it already, emissive is using whatever color you like. I was already thinking it might be hardware/driver related. I asked someone in the community to confirm this and he had the same issues, he is using a 1050 TI and I got a Radeon R9 270x with the newest driver 17.10, I also tried 17.7.2.
I think this is intended behavior and happens because the mesh renderer is fighting with the mesh bounds. I can completely remove the flickering by increasing the bounds extension in the Static Mesh Editor. With these updated bounds I can use the mesh for the preview in the Material Editor and everything works. More information can be found in this answer and partially here.