Threads I have read no longer showing in a different colour?

[magimedi]

Started this morning - am on desktop + firefox.

Do you mean in active magi?

So the ones you've clicked on are still blue rather than purple?

Is anyone else having this issue?

In active & when I go to the chat forum or AIBU or any other onne.

Same for me on mobile site

I've had it for ages (months probably) - some do and some don't!
It happens in active and threads I'm on.
Desktop and IE

I've had it too but it's inconsistent.