In nature, most males are the colorful one and the females are not as colorful. (not as pretty) Why? Because the males want to attract the females and mate. If you look at a peacock the ones with the "eye" feathers are the male (the blue ones) the brown non-colorful ones are the female peacocks. So my guess is that the colorful fish are the males and the non-colorful ones are females. But don't take my advice, I don't know I'm right! it's just a guess!
I hope it helped (even though it was a guess!
angelfish
One example of a brightly colored fish that starts with an "o" is the Ocellaris Clownfish, also known as the "false percula clownfish." These fish have vibrant orange bodies with white stripes.
Although I'm not sure what you mean by "deep" body, Betta fish, or Siamese Fighting Fish, or Rumble Fish (if you're S.E. Hinton) are thin, brightly-colored (domestically bred males tend to be more colorful), and have long, wavy fins.
Some different species of birds
brightly colored males:)
Because they are trying to warn predators that they are poisiness
To attract pollinators.
A brightly colored blanket or cloak is called a serape. It is worn in Mexico, Central America and South America.
Cocks were created with brightly colored feathers to make them noticeable to females who may be attracted to the colors.
The fear of brightly colored animals is known as "chromophobia." This term is derived from "chromo," meaning color, and "phobia," indicating fear. While it can encompass various aspects of color, it specifically relates to the aversion or fear of brightly colored creatures, which may evoke feelings of anxiety or discomfort in some individuals.
i do not know sorry
Some names of brightly colored marbles are Rainbow, Sunburst, Electric Blue, and Candy Swirl.