Eran Amir filmed this video in color, so why are most of the objects in grey? Well, turns out, he actually painted the whole room and its contents (including himself) in shades of grey.
All? Not quite, since the orange juice in the greyed out box is still orange and appears so when it is poured out into a glass container. Likewise the bubble gums balls, the underside of the playing cards, the other side of the bottle of coke, the inside of the watermelon, etc. etc. all are pregressively revealed in their original color.
It’s a genial concept and, best of all, there’s no digital manipulation involved.