My DW6900 wanted me to try it so I did
Bought some A4 colored transparent paper (is there a word for it ?)
Cut it to fit the inside of the inner dial (succeeded after a few)
3. Pasted it under the inner dial (after taking out the movement)
I didn't needed any glue, the inner dial is a little sticky and the movement will hold it too).
Now, introducing the Red LCD 6900 >
Not super-legible in low light...
But no problems outside, on a sunny day
The only real problem is the hair, but I think it's me, not the 6900
Hope you like it,