In case you don't know, the colours of the Ukrainian flag come from the direct association between the blue of the sky and the yellow of its vast wheat fields.
The narrative use of colour in film serves as a guide to illustrate the psychology of colour and demonstrate how appropriate combinations create powerful palettes.
The colors, speaking of visual communication, expand the meaning of the message making it sound, like a melody. Because the colors being light waves produce vibrations in us as well as sound.