Throughout the game, Crash will collect Gem Tokens of various colors by completing Crate Challenges. Once he has a complete set of all one color, he can sail to Gemstone Island and unlock that color Shrine, granting him access to a special area where the colored Gem awaits.
This video shows the early stages of building this area in timelapse with post commentary. We are trying this out as a new format. Let us know what you think.