If one looks closely when SpongeBob points his left finger while singing Sweet Victory, they can see the Best Friends Forever Ring from "The Secret Box."
This, "Frankendoodle ," "The Secret Box" and "Krusty Love" all have SpongeBob with a darker shade of yellow, matching his colors in Season 1. It's possible these episodes were animated before the animation directors decided to change SpongeBob's yellow to be much brighter.
This is further supported by the fact that SpongeBob's colors change during the Bubble Bowl performance to his newer color palette.
This is considered the best SpongeBob SquarePants episode of all-time.
The following scenes from this episode have become popular memes: