I can't figure out how the white balance preview works on the Olympus OM-D E-M1 Mark II, and it is not covered in the official manual.
If you go to the LV control panel, select either of the A/G WB compensation controls, then press OK, it puts you into the WB preview screen, but it is black except for the A/G adjustment bars on the right hand side. At the bottom is a note that says "white balance preview" and then has an icon that looks like the shutter release, but if I depress the shutter release half way, then the adjustment bars disappear and it just goes to the plain LV preview.
I assume that the WB preview is supposed to allow the operator to adjust WB compensation while viewing the effect on the LV screen, but I can't figure out how to get this to work, if indeed that is how it is supposed to work.