Color is of interest for filmmakers as well.
When Clems hair is red and orange, this is in the past.
When Joel and Clementine first meet, her hair is green.

The Grand Budapest Hotel (2014) | IMDb
He explained this reasoning was because of something he learned while directingThe Color Purple.
ColorPurpleshouldve been in black-and-white.
I was accused of beautifyingColorPurplebecause it had such a bright palette for such a dark subject, he recalled.

vibrant shades represent joy and whimsy while the darker hues communicate sadness or conflict).

Amélie| IMDb

Focus Features

Universal Pictures

The Grand Budapest Hotel| IMDb