I tested window.navigator.userAgent, and it gave useful values on my Kindle and in Chrome on my Likebook Mars, but the value it gave in Firefox on my Likebook Mars did not mention the device by name. I cleared the cache in Chrome on my Likebook Mars, but I still saw a black bar over the board.
Please try what it does on the Kindle.
It is only the Likebook Mars that displays red as black. The Kindle displays red as white, which leaves the text legible. However, I now see the text in a grey bar on the Kindle, and I think that previously I just saw the text against the same white background as the rest of the comment.
I tested window.navigator.userAgent, and it gave useful values on my Kindle and in Chrome on my Likebook Mars, but the value it gave in Firefox on my Likebook Mars did not mention the device by name. I cleared the cache in Chrome on my Likebook Mars, but I still saw a black bar over the board.
It is only the Likebook Mars that displays red as black. The Kindle displays red as white, which leaves the text legible. However, I now see the text in a grey bar on the Kindle, and I think that previously I just saw the text against the same white background as the rest of the comment.