I noticed an oddity in Mark 6:10: The words "he said" appear in black. I've attached a screenshot.
I'm relatively certain that this is related to the red lettering, since on either said of "he said" are the words of Jesus.
If I turn red lettering back on, Jesus' words are in red, but "he said" is still in black, even with the text color set to brown.
None of the other English translations I use put "he said" or similar between two quoted sections in Mark 6:10, so I can't easily tell if this is an issue with all translations or not.