Hey az93 , I can't see anything wrong with your nodes. The pink would normally indicate a missing texture.
I can see you have Eevee selected in the material output node, make sure you also have Eevee selected in the render properties. I normally leave the material output at the default , All.
Double check your nodes, make sure you don't have duplicates, one on top of the other.
Try saving your work, close Blender, and then open up the file again in Blender. It may be a hardware issue, memory probably if it is. Saving, closing and reopening Blender will clear out anything being held in the memory.
I believe another member experienced a similar issue which came down to hardware capabilities. I know Eevee supports a finite number of nodes in material networks and will turn pink once that threshold is crossed. But I think I remember 
duerer discovering that it can even turn pink sooner depending on PC hardware.
Am I right about this duerer?