It was a bright sunny day in phoenix (severe drought 122 days with out rain) I was using the navigation and could not see it well. I was playing with the dim control for the dash lights and found out if you roll it to the max brightness it will go one more click, now the navigation screen is in reverse mode. IE white background with black letters. It was very easy to see then. I am sure you other brilliant prius users have found this out but it sure surprised me.
The white background is daytime mode, and the dark for night so it's not too bright. I've never tried to use the dark screen during the day
