Anonymous ID: 6505b7 Feb. 19, 2019, 8:54 p.m. No.5278260   🗄️.is 🔗kun

https://en.wikipedia.org/wiki/Technicolor

The key is a black and white background layer used to add contrast lacking in the cyan/yellow/magenta overlay.

Wizard of Oz.

https://www.youtube.com/watch?v=Mqaobr6w6_I

@4:00