Hmmm. The beauty of a flower is not in the flower alone, but in the bee that is attracted by the colors to feed, thus to enable the flower to reproduce. The result is a win/win situation for flower and bee.
From my brief reading, the bright colors of tropical fish are "key to astoundingly complex strategies to attract mates, repel rivals and hide from predators."
https://www.bennington.edu/sites/def...ef%20fish-.pdf
Alas, we humans find some too beautiful which, I understand, has resulting in depletion of some species (such as "Nemo") to fill aquariums.
It is a dog eat dog, and fish eat fist, and man capture fish world out there! Beautiful colors and patterns play a part in all of it. That is Samsara, this sometimes win/lose, live/die world. Sometimes win/win, sometimes win/lose ... maybe even sometimes lose/lose.
Buddhism does not have one simple explanation for beauty. It simply notes that beauty exists in both the beheld AND the eye of the beholder. However amazing that our human eyes evolved to be so finely tuned to the wavelengths of light, able to experience such bright colors and patters. The bright colors and patterns do not exist without BOTH your eyes and brain AND the atoms and photons which transmit those patterns.
This world is complex, it is all of us, people and flowers and bees and coral reefs and fish. That is the true Beauty if you ask me. The Great Win/Win.
Gassho, J
STLah