For some odd reason, the blue bowl is the preferred water bowl. I don't know why. The pink bowls were purchased for Jujube. The tan and blue bowls are Loki's.
Every meal time, Jujube eats out of one of the pink bowls; Loki eats out of the tan bowl. After finishing his food, Loki drinks out of the blue bowl. Jujube goes away; she does not drink the water that is in the pink bowl. Instead, she waits until after Loki is done drinking, and then proceeds to drink out of the blue bowl. Here's a picture of her drinking out of the blue bowl.
Why is the water in the blue bowl better?