Trinity

Trinity Mark is a special action present in Kingdom Hearts. While traveling between Worlds, Sora will occasionally come across a colored mark composed of three hearts connected by a circle, which causes the bottom command box to change to "Trinity". Activating this command will allow Sora, Donald and Goofy to perform an action matching the mark's color. By using Trinity Marks, the party can open new paths or obtain rare treasures. There are a total of five different Trinity colors Sora, Donald, and Goofy can learn throughout the game.

As they are the main party and closest friends, the Trinity command will only appear if Sora, Donald, and Goofy are the party members; if another character, such as Aladdin or Ariel is in the party instead, the command will not activate.

Trinity marks are required to complete Jiminy's Journal and progress the storyline. Finding and activating all of them is not required to complete the game, nor to unlock the bonus ending movie. In addition, all Trinities can be gone back and retrieved if they are missed at any point in the game.

Note:

The one exception is the red Trinity in Halloween Town at Oogie's Manor; it must be activated on the first journey through Oogie's Manor, as it becomes inaccessible after the Oogie's Manor boss is defeated. If you did not get the Red Trinity your first time through, and are trying to get them all, it is now impossible. This issue was fixed in Kingdom Hearts: Final Mix, but there was no such solution implemented for the original game.

Blue
The first obtained in the game and by far the most common, this Trinity is learned after defeating the Guard Armor boss in Traverse Town. The blue marks represent the ability Trinity Jump; Sora, Donald and Goofy bounce on the floor, shaking treasure loose from somewhere above them, or accessing higher levels. Although this is the first mark to be learned, activating blue Trinities are not required to complete the game.

Red
Second to be discovered, after sealing the Keyhole at Deep Jungle, the red marks are for Trinity Charge. Sora, Donald and Goofy will charge at a wall or barrier and break it, revealing a new path. Trinity Red is required at some points in the game to progress the story, especially in Traverse Town.

Green
The third Trinity mark, green Trinity marks are activated after Agrabah is locked. They represent Trinity Ladder, where Sora, Donald, and Goofy climb on top of each other to reach something up high. The green Trinity is required at one point in Neverland; it must also be used to access the Moogle shop above Cid's store in Traverse Town and activate Item Synthesis.

Yellow
The fourth mark to be learned and the rarest of them with only a total of four in the game, yellow Trinity marks activate Trinity Push, allowing Sora, Donald and Goofy push a heavy object around. In order to obtain this mark, Sora must win the Hercules Cup in Olympus Coliseum; he promptly puts it to good use by using it to help him lock the Coliseum's Keyhole.

White
The fifth and final mark that Sora, Donald, and Goofy learn is Trinity Detect; the trio raise and point their weapons, summoning a treasure chest. It is learned after Riku is defeated for the first time in Hollow Bastion. This trinity is not required to complete the game, but does net some useful things, especially the Lady Luck Keyblade and the Violetta staff for Donald.

List of Trinity Marks by Color
For a list of the Trinity marks in each World, check the Trinity section found in each World article.

Blue Marks

 * Traverse Town: First District, by the World Exit
 * Traverse Town: First District, by the Cafe.
 * Traverse Town: Third District, head towards the ramps on the sides of the wall, fountains.
 * Traverse Town: Merlin's House, in Third District there is a door with a flame, use the fire spell, it's in the house by the chalkboard.
 * Wonderland: Lotus Forest, in the groove near the entrance.
 * Wonderland: Lotus Forest, further towards the second entrance.
 * Olympus Coliseum: By the Gate, on the left side.
 * Deep Jungle: In the campsite.
 * Deep Jungle: High platform in Climbing Trees.
 * Agrabah: Bazaar, atop a platform.
 * Agrabah: Cave of Wonders, inside the Silent Chamber.
 * Monstro: Mouth, atop a platform.
 * Monstro: Throat, on one of the spiral platforms.
 * Monstro: Chamber 5.
 * Hollow Bastion: Great Crest, after defeating Maleficent Dragon.
 * Hollow Bastion: Underway Dungeon

Red Marks

 * Traverse Town: First District, alleyway.
 * Traverse Town: Second District, by the gates to the Waterway.
 * Traverse Town: Second District, atop the Gizmo Shop.
 * Agrabah: Cave of Wonders, inside the Treasure Room.
 * Halloween Town: Entrance of Oogie's Manor. Only accessible before defeating Oogie Boogie. In Kingdom Hearts: Final Mix, this Trinity Mark is situated at an arch near the river leading towards the exit of the manor area.
 * Hollow Bastion: Entrance Hall, second level, in front of the statue.

Green Marks

 * Traverse Town: First District, Cid's Accessory Shop.
 * Wonderland: Rabbit Hole, near the Save Point.
 * Wonderland: In the Bizarre room (when small), in the fireplace.
 * Olympus Coliseum: In front the Olympus Gates.
 * Deep Jungle: In the center of the Treetop area.
 * Agrabah: Storage Room, off the Plaza.
 * Monstro: Gepetto's shelter, reachable via High Jump.
 * Neverland: Ship's Cabin, at the entrance of Hook's Cabin.
 * Hollow Bastion: Second floor of the Library.

Yellow Marks

 * Traverse Town: Behind Merlin's House.
 * Olympus Coliseum: Lobby, by the stone block.
 * Agrabah: Cave of Wonders, in the Hall.
 * Neverland: Ship's Hold, on a platform halfway up to the top.

White Marks

 * Traverse Town: Secret Waterway, along Leon.
 * Wonderland: Lotus Forest, on the side of the picture in Bizzare Room.
 * Olympus Coliseum: In front of Coliseum Gates.
 * Deep Jungle: Waterfall Cavern, in front of the Keyhole.
 * Agrabah: Cave of Wonders, main entrance.
 * Monstro: Chamber 6.
 * Halloween Town: Moonlight Hill
 * Atlantica: Triton's Palace, in the center beneath the conch shell.
 * Neverland: Up on the Poop deck of the ship.
 * Hollow Bastion: On the peak of the platform in Rising Falls.

Trivia

 * Trinity has always been at the beginning of a special attack done by Sora, Donald, and Goofy.
 * A Green Trinity symbol represents friend cards at the top left corner of the screen in Kingdom Hearts Re: Chain of Memories.