No, you're correct about the rules and how it works. What I'm saying is that if I have one fountain dip "saved", and I get another Fountain Faerie quest. Then, I can either abandon the new quest, or dip my pet into the fountain before completing the new quest if I decide to do that. Which means if I have a pet take a dip and then complete the quest, I'll have a trip to the fountain "saved" again until the next time I want to change a pet's color.
Sorry if I wasn't clear with my initial post on this.