Self-illumination on material, texture viewable in viewport by default

When doing signage in renders, it's crazy annoying not being able to see the bitmap displayed in the viewport as soon as the Self-illumination multiplier of the material has been changed to anything bigger than 0. It just becomes a white surface in the viewport.

So we either have to turn it to 0 again (and remember to change it back to correct number after adjustments to signage mapping) OR change the color slot to black instead of white which also works.

Having the color to be black by default might sound like a quick solution, but could also be annoying to others who just want the material to emit white light as standard.

The material preview on the material looks fine with self-illumination on, but something happens in max viewport to not show it correctly. We just want to see the normal bitmap in the viewport. Completely flat, as we have to render anyways to see how it looks in the scene.