At the end of the game, your score is whichever color you have the LEAST points in, meaning you have to play a balanced game, bringing all your colors up as far as possible. You may have all colors up to 18 but one, but if that final color is 2, then your score is 2.
At game end, all of my colors had scored well, including two (orange and green) maxed out at 18. Carol's purple and red scores were her Achilles heel.
Coming up: We move into the ocean currents to mate fish, yes, mate fish, in The Reef.