I have an Owl Exchange account and a gmail account on Thunderbird 78.6.1. I was running 68.12.1 until very recently. I'm (obviously) running a dark theme (DeepDark for TB 78). On the Owl account, the messages are white text with a grey alternating background. On the gmail account, it used to be the same, but for the last several days, it's looked (mostly) like the attached image instead: black text on grey alternating background. Most confusing, a few messages are still white. Note I have blurred email addresses on the attached image. I don't believe this is an addon issue; it was fine with these addons (in TB 68) for a long time. I feel like I accidentally tapped some key that caused this, but I could very well be wrong. Thanks KSH