I mean, the themes of ‘PoA’ are somewhat more mature, so the noirish look was warranted. And from what I remember, it wasn’t just a blue-and-orange palette, like in many modern films, but a pretty colorful one inside that noir feel.

Cuarón also doesn’t do such palettes everywhere. ‘Y tu mamá también’ is very colorful, while the dystopian ‘Children of Men’ is accordingly subdued. So it was a choice appropriate to the events in the film, just like the installments later in the series also get darker.