diff --git a/doc/APIreference.rst b/doc/APIreference.rst
index 9f4baa52..307aeea3 100644
--- a/doc/APIreference.rst
+++ b/doc/APIreference.rst
@@ -873,7 +873,7 @@ mjtRndFlag
        mjRND_FOG,                      // fog
        mjRND_HAZE,                     // haze
        mjRND_SEGMENT,                  // segmentation with random color
-       mjRND_IDCOLOR,                  // segmentation with segid color
+       mjRND_IDCOLOR,                  // segmentation with segid+1 color
 
        mjNRNDFLAG                      // number of rendering flags
    } mjtRndFlag;
diff --git a/include/mujoco/mjvisualize.h b/include/mujoco/mjvisualize.h
index 4237165b..3295a135 100644
--- a/include/mujoco/mjvisualize.h
+++ b/include/mujoco/mjvisualize.h
@@ -133,7 +133,7 @@ typedef enum mjtRndFlag_ {        // flags enabling rendering effects
   mjRND_FOG,                      // fog
   mjRND_HAZE,                     // haze
   mjRND_SEGMENT,                  // segmentation with random color
-  mjRND_IDCOLOR,                  // segmentation with segid color
+  mjRND_IDCOLOR,                  // segmentation with segid+1 color
 
   mjNRNDFLAG                      // number of rendering flags
 } mjtRndFlag;