Strange lighting effects throughout the movie - purple lips?

There must've been a shortage of light bulbs in that town, because so many of the interior scenes seemed so dark, gloomy, and weirdly lighted. The high school pool area, for example, seemed to be constantly in a state of half-darkness. I'll buy that for the scenes late at night when Ben and Madison snuck into the pool, but in other scenes, like when the scouts come to check out the swimmers, or when they show the swim meet in the closing scenes, it's still very dimly lighted. Same with the hospital corridors, as well as some of the high school corridor scenes in the middle of the day.

I know it was all done for maximum 'suspense' effect, but it had the perhaps unintended side effect of making the characters' lips look a kind of bizarre lavender/purple color.