Thanks for your quick answer.
Ok, knowing that, i may improve a bit more and keep the very light greeninstead of the pure white then… same goes for the indices and numbers. (If I understand well, it's only a consumption issue… so the less pixels lighted, the better, but color does not really matter…)
In this watch, even in "normal" mode, the indices are dimmed progressively during the night. they fade out between 6PM and midnight, and fade in again between midnight and 6 AM. Between 6AM and 6PM it's full bright.
(expressions are not very easy to manage… and I'll open another post for a specific question