To be rainbow in Deltarune RP on Roblox, the usual way is to use the game’s morph color or a rainbow-style color setting if the server supports it. A recent Roblox community tutorial and related posts show players using a /morphcolor command with specific color codes, and another guide discusses rainbow effects as a color-changing feature in Checho’s Deltarune RP.

What to try

  • Open the game chat.
  • Check whether the server lets you change morph color with a command like /morphcolor.
  • If rainbow is supported, look for a special code, toggle, or role tied to cosmetics or customization.
  • If the game does not support rainbow directly, it may only be available through admin tools, badges, or a special morph.

What the public info suggests

  • One tutorial lists several morph color codes for the game, which means color customization is at least partly command-based.
  • The Roblox group page says some special roles are based on time spent in-game, so rainbow may be linked to progression or a role unlock rather than a free command.
  • A separate discussion about rainbow effects in Roblox shows that “rainbow” can also mean a scripted visual effect, not just a single color code.

Example

If the game uses command-style color changes, a player might enter a color code such as a blue, green, red, or remove-color value rather than a literal “rainbow” command. That means “rainbow” may be a cosmetic effect you unlock or script, not a normal chat command.

Safer note

Some videos on the topic include joke steps or obviously fake instructions, so it is better to rely on the game’s own commands and official community info.