diff --git a/public/lib/adminlib.php b/public/lib/adminlib.php
index abc0985ea3a..c68705c8cf2 100644
--- a/public/lib/adminlib.php
+++ b/public/lib/adminlib.php
@@ -10612,13 +10612,13 @@ class admin_setting_configcolourpicker extends admin_setting {
             return $data;
         } else if (in_array(strtolower($data), $colornames)) {
             return $data;
-        } else if (preg_match('/rgb\(\d{0,3}%?\, ?\d{0,3}%?, ?\d{0,3}%?\)/i', $data)) {
+        } else if (preg_match('/^rgb\(\d{0,3}%?\, ?\d{0,3}%?, ?\d{0,3}%?\)$/i', $data)) {
             return $data;
-        } else if (preg_match('/rgba\(\d{0,3}%?\, ?\d{0,3}%?, ?\d{0,3}%?\, ?\d(\.\d)?\)/i', $data)) {
+        } else if (preg_match('/^rgba\(\d{0,3}%?\, ?\d{0,3}%?, ?\d{0,3}%?\, ?\d(\.\d)?\)$/i', $data)) {
             return $data;
-        } else if (preg_match('/hsl\(\d{0,3}\, ?\d{0,3}%, ?\d{0,3}%\)/i', $data)) {
+        } else if (preg_match('/^hsl\(\d{0,3}\, ?\d{0,3}%, ?\d{0,3}%\)$/i', $data)) {
             return $data;
-        } else if (preg_match('/hsla\(\d{0,3}\, ?\d{0,3}%,\d{0,3}%\, ?\d(\.\d)?\)/i', $data)) {
+        } else if (preg_match('/^hsla\(\d{0,3}\, ?\d{0,3}%, ?\d{0,3}%\, ?\d(\.\d)?\)$/i', $data)) {
             return $data;
         } else if (($data == 'transparent') || ($data == 'currentColor') || ($data == 'inherit')) {
             return $data;