
Vegetoid introduces this attack type, and it is also used by Woshua, Parsnik, Whimsalot, and the human SOULs during the Photoshop Flowey battle. Some enemies require the protagonist's SOUL to collect green attacks so that the protagonist can spare them. Green attacks heal the protagonist, progress the battle in some way, or both. Red is associated with the protagonist's and the fallen human's SOULs, which may imply that the warnings are protecting the protagonist's SOUL. Mad Dummy's red attacks deal damage as if they are white. Ice Cap is the first monster to introduce red attacks. The warning can take on several forms, such as an attack itself flashing red (as used by Ice Cap and Undyne), a simple red outline bordering the area of the attack (as used by Photoshop Flowey and Sans), or a red rectangle with an exclamation point in the center and a flashing sound effect (as used by Mettaton EX, Asgore, and Asriel). Red attacks usually do no damage but are used to warn of upcoming attacks. Gray is not associated with a soul color, and may simply reference doing nothing in battle.

SORRY." One of Ice Cap's attacks also features gray attacks (in addition to red and white) Mettaton EX uses a gray attack to spell out "Happy Breaktime!". Napstablook introduces this attack type they spell out " REALLY NOT FEELIN UP TO IT RIGHT NOW. Gray attacks deal no damage and are used for aesthetic purposes, such as spelling out messages in the Bullet Board.

The multicolored attacks used by Undyne, Photoshop Flowey, and Asriel Dreemurr function the same as white attacks. The only way to counter white attacks is by dodging them. White attacks hurt the protagonist if their SOUL collides with them.
