We were working for a big soda brand that was opening a branded beach party place. Part of the project involved making an illustrated map about the area. The client was happy with it, except for one detail:
Client:  Can you change the color of the water from blue? It’s the color of Pepsi.

Me: What colour would you prefer?

Client: How about green?

Me: We used that for the land.

Client: Makes sense. Red?

Me: Red water?

Client: Yeah.

Me: Well… okay, but that’s also a colour associated with Coca Cola.

Client: Damn, what colour do most people associate with water?

Me: Uh… blue, usually.