diff --git a/src/Colours/ColoursApiRoutes.php b/src/Colours/ColoursApiRoutes.php
index 1710b177..6a71763f 100644
--- a/src/Colours/ColoursApiRoutes.php
+++ b/src/Colours/ColoursApiRoutes.php
@@ -37,6 +37,9 @@ final class ColoursApiRoutes implements RouteHandler {
                 'default' => true,
                 'transform' => fn($preset) => $preset->colour,
             ],
+            'rgb' => [
+                'transform' => fn($preset) => $preset->colour & 0xFFFFFF,
+            ],
             'css' => [
                 'default' => true,
                 'transform' => fn($preset) => (string)$preset->toColour(),