Colors

Emmanuel & Mérovée : Geology

https://geology.com/minerals/hematite.shtml

https://geology.com/minerals/limonite.shtml

Alexis, Arthur, Raoul : Chemestry

https://www.thoughtco.com/pigment-definition-4141440

Paul & Lancelot : History

https://www.earthdate.org/colorful-history-of-paint