diff --git a/src/SlashCommands.js b/src/SlashCommands.js
index 0dc717a6fe..06120b183f 100644
--- a/src/SlashCommands.js
+++ b/src/SlashCommands.js
@@ -722,7 +722,7 @@ export const CommandMap = {
 
     rainbow: new Command({
         name: "rainbow",
-        description: _td(""),
+        description: _td("Sends the given message coloured as a rainbow"),
         args: '<message>',
         runFn: function(roomId, args) {
             if (!args) return reject(this.getUserId());
@@ -732,7 +732,7 @@ export const CommandMap = {
 
     rainbowme: new Command({
         name: "rainbowme",
-        description: _td(""),
+        description: _td("Sends the given emote coloured as a rainbow"),
         args: '<message>',
         runFn: function(roomId, args) {
             if (!args) return reject(this.getUserId());
diff --git a/src/i18n/strings/en_EN.json b/src/i18n/strings/en_EN.json
index 8534091176..be82c5427a 100644
--- a/src/i18n/strings/en_EN.json
+++ b/src/i18n/strings/en_EN.json
@@ -178,6 +178,8 @@
     "The signing key you provided matches the signing key you received from %(userId)s's device %(deviceId)s. Device marked as verified.": "The signing key you provided matches the signing key you received from %(userId)s's device %(deviceId)s. Device marked as verified.",
     "Displays action": "Displays action",
     "Forces the current outbound group session in an encrypted room to be discarded": "Forces the current outbound group session in an encrypted room to be discarded",
+    "Sends the given message coloured as a rainbow": "Sends the given message coloured as a rainbow",
+    "Sends the given emote coloured as a rainbow": "Sends the given emote coloured as a rainbow",
     "Unrecognised command:": "Unrecognised command:",
     "Reason": "Reason",
     "%(targetName)s accepted the invitation for %(displayName)s.": "%(targetName)s accepted the invitation for %(displayName)s.",