LED speed limit sign not easy to see

For the majority of the journey between J10-J12, the bright white speed LED circle, on the gantry, makes the speed number very difficult to see until you are just approaching it. When the signs came on to show a lane closure for workman in the road, they were easy to see as they are more orange based. I think this needs reviewing as the speeds are very difficult to see. This is the first time I have used the motorway at night for at least 2 years so only just had experience