Those small fish eggs of many colors all come from the same fish — the flying fish. The roe is actually bright red in its natural color, but other ingredients are used to produce the many different colors you’ll see atop maki sushi rolls. For example, yuzu can be used to color the roe yellow, and squid ink to color the roe black.
Tobiko isn’t just a garnish either. It is also served as sushi or sashimi or added to other dishes such as salads. The fish eggs have a crunch that also adds texture to maki rolls and other dishes and exhibit a salty, smoky, and slightly sweet flavor.