the white bars are the CHT temps... they turn yellow and red toward the right according to the temps set up for the sensor... as tony pointed out they are only shown in the combined compressed CHT/EGT view... they are shown in both lean and normal mode for this view.
here is a shot after engine shut down in normal display mode for reference.
Stephen, you right all the way. Took my 10 for a spin and messed with all the possible layout to realize that the bars reflected what you mentioned.
Thank you