diff --git a/docs/how-to-guides/themes/theme-json.md b/docs/how-to-guides/themes/theme-json.md
index 0990c618ea9f4..6e751aa2e19ff 100644
--- a/docs/how-to-guides/themes/theme-json.md
+++ b/docs/how-to-guides/themes/theme-json.md
@@ -169,6 +169,7 @@ The settings section has the following structure:
 	"settings": {
 		"color": {
 			"custom": true,
+			"customDuotone": true,
 			"customGradient": true,
 			"duotone": [],
 			"gradients": [],
@@ -220,6 +221,7 @@ The settings section has the following structure:
 		},
 		"color": {
 			"custom": true,
+			"customDuotone": true,
 			"customGradient": true,
 			"duotone": [],
 			"gradients": [],