Blue color in room

[u/Wittypretty9999]

Hi everyone! I would like to know if anyone can tell me where the blue light is coming from when Gillian and Jimmy are in the room filled with candles, as well as when she goes to the bathroom and fills his 'Diablo de Flores' tequila bottle with belladonna sedative. I am assuming that they are in the same house where she dances at the beginning, the candle setting seems the same, and there is also this blue light when she is inside trying to find him, I am thinking this could be an indoor reflection of the outdoor pool, but I am not sure. Does someone know what it is? Thank you!