diff --git a/doc/news/DM-45975.doc.rst b/doc/news/DM-45975.doc.rst
new file mode 100644
index 000000000..64048682d
--- /dev/null
+++ b/doc/news/DM-45975.doc.rst
@@ -0,0 +1 @@
+Updated config schema enumeration of monochromator gratings
diff --git a/python/lsst/ts/standardscripts/auxtel/calibrations/power_on_atcalsys.py b/python/lsst/ts/standardscripts/auxtel/calibrations/power_on_atcalsys.py
index 0cec462fb..61fd6a6be 100644
--- a/python/lsst/ts/standardscripts/auxtel/calibrations/power_on_atcalsys.py
+++ b/python/lsst/ts/standardscripts/auxtel/calibrations/power_on_atcalsys.py
@@ -93,7 +93,7 @@ def get_schema(cls):
                 minimum: 0
 
               grating_type:
-                description: Grating type for each image. The choices are 0=mirror, 1=blue, 2=red.
+                description: Grating type for each image. The choices are 0=mirror, 1=red, 2=blue.
                 type: integer
                 enum: [0, 1, 2]
                 default: 0