Unusable letters do get painted dark gray. Is that not visible to you? Can you send a screenshot?
I already did today's dordle and haven't found a way to go back to view it. It just shows my results. I can take a screenshot tomorrow. When I go to free dordle I can see that the letters are grayed out. But not for daily dordle. Unless it's something to do with dark mode but I have tried turning my brightness up and switching it from dark mode so I don't know.
I'll post a picture tomorrow unless you can tell me how to view the one I already did.
Thanks.
It seems that it might have something to do with the setting that darkens the phone to a black screen at sunset. I usually do dordle before the sun comes up but here is today's and you can see that the letters are grayed out.
I also posted another where you can see that the screen does not show that.
I put this picture down lower since it is today's dordle.