Asus Laptop N550JK. Intel® Core™ i7-4700HQ
Operating system: Fedora 28, Kernel ->4.19.4-200.fc28.x86_64
Gnome: Version 3.28.2
OS Type: 64-bit
Graphics card: GeForce GTX 850M/PCIe/SSE2, (add. info. It has Optimus)
blender 2.8, 26d5a3625ed, 2018-11-29
blender 2.79b also has the similar problem.
Short description of error
Having nvidia drivers installed as described by negative 17, after waking from a OS sleep while blender is opened, blender kind of looses its connection with graphics driver and all the functionality of blender associated with NVIDIA graphics driver becomes corrupted. Thus making the color of objects in view port null, when bpy.data.screens["Layout"].shading.type is set to "LookDev" or "Rendered". If I change the render engine from Evee or Cycles to Workbench or in Cycles change the Device to CPU, the view port colors becomes functional but the remains for the GPU Device or Evee selected. Before sleeping the OS, CyclesPreferences.compute_device_type shows both CPU and GPU for selection, but after waking system it disappears.
PS: I have tried all other graphics driver repositories except direct installation of the files downloadable from NVIDIA website.
Closing and reopening or killing the blender process in terminal doesn't bring back the GPU support but solves the white color problem.
Exact steps for others to reproduce the error
Making the problem:
From the default startup -> change view port display method to LookDev or Rendered -> sleep the fedora by fn+F1 keystroke -> wake the computer
My current work around:
Close blender and open it again.