The courtship ritual adds charm to the life of the seahorse.

The type of seahorse in this photograph was not identified by the photographer, who in his caption stated:

Every morning, seahorse couples do a mating dance in order to reinforce their permanent bond. They will mate for life.

Photo attribution: By Gulf Specimen (Own work) [CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons

The Wikipedia (link below) mentions the color change that seahorses may undergo:

Courtship

Before breeding, seahorses may court for several days. Scientists believe the courtship behavior synchronizes the animals’ movements and reproductive states so the male can receive the eggs when the female is ready to deposit them. During this time, they may change color, swim side by side holding tails or grip the same strand of sea grass with their tails, and wheel around in unison in what is known as a “predawn dance”. They eventually engage in a “true courtship dance” lasting about 8 hours, during which the male pumps water through the egg pouch on his trunk which expands and opens to display its emptiness. When the female’s eggs reach maturity, she and her mate let go of any anchors and drift upward snout-to-snout, out of the seagrass, often spiraling as they rise. They interact for about 6 minutes, reminiscent of courtship. The female then swims away until the next morning, and the male returns to sucking up food through his snout.[14] The female inserts her ovipositor into the male’s brood pouch and deposits dozens to thousands of eggs. As the female releases her eggs, her body slims while his swells. Both animals then sink back into the seagrass and she swims away.

Wikipedia notes that although monogamy in fish is uncommon, it may exist for some species of seahorses, though species may differ in that respect.

For more about seahorse origins and life cycle, see the Wikipedia article here.