They’re a plant person, and they run a farm that sells green, yellow, and brown items exclusively. It is appropriately titled “Green Shit Farm” (the tagline of the farm is “Only buy Green Shit. Only trust Green Shit™”). Their hair is leaves and their body is plant.
I made this character up cuz I wanted to play Stardew Valley again, but I wanted to play hardmode. I was originally just going to sell green items, but that turned out to be incredibly difficult, so I accepted yellow and brown as well, because they’re kind of green.
Blue is the true pair for green. Brown and yellow have their own thing among themselves.