I noticed the color of the "before calibration" graph has the left and right channels with pretty similar colors. If you were to hue shift one and increase the saturation, they are a lot easier to distinguish between.
The same rule could also apply to the phase plot and the correction plots, which are even harder to read as both channels have the same exact RGB values. I think a good idea would be to have the left channel as always the dark and unsaturated one, and the right channel as the hue shifted, saturated one. That theme was already applied if you look at left and right in the output category labels.
I think working with orange (phase) would be harder to find a compliment for, but you could change one of the channels to red or pink. For Before and Correction, I made a mock up, but I couldn't include Phase because my phase isn't drastically altered (hope it uploads in full resolution, can't tell when making a forum post here).