So while waiting for an new Illustrator Functionality to come the only one Actual Solution is of Making a Truly Simulated Background where you can Clearly Perceive also White Strokes and Fills:
- Window > Layers
- Create a New Layer and Place it Below all others
- On the Layers Panel Click to Select the New Layer
- Select the Rectangle Tool
- Set the Rectangle-Background's Color
- Draw a Rectangle larger than your Document size
- Lock your New Layer so it will not Interfere with your Work
Now you are Free to Stroke and Fill also with Whitish Colors ;)
Extra Indications:
HOW-TO Getting-Started and Running with Illustrator CS