This suggests to me that this bug might really be revealing that one of our foreground-color-variables (whichever one we were using here) might be mistakenly the wrong value, specifically under the default theme with Ubuntu Appearance Settings "Style:Light"...
Bug 1812840 Comment 9 Edit History
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This suggests to me that this bug might really be revealing that one of our foreground-color-variables (whichever one we were using here) might be mistakenly the wrong value, specifically under the default theme with Ubuntu Appearance Settings "Style:Light"... [EDIT: Good news, turns out this is mostly fine. See notes in comment 11 for how we end up with mismatching foreground/background colors here.]