diff --git a/schemas/block-inserter-payload.schema.json b/schemas/block-inserter-payload.schema.json
index 3bdc5a605..090d8583d 100644
--- a/schemas/block-inserter-payload.schema.json
+++ b/schemas/block-inserter-payload.schema.json
@@ -75,6 +75,10 @@
 					"type": [ "string", "null" ],
 					"description": "SVG markup as a string, or null when the block has no renderable icon."
 				},
+				"iconForeground": {
+					"type": [ "string", "null" ],
+					"description": "CSS color (hex or rgba) applied to the SVG icon's foreground, or null when the block uses default tinting."
+				},
 				"frecency": { "type": "number" },
 				"isDisabled": { "type": "boolean" },
 				"isSearchOnly": { "type": "boolean" },
diff --git a/src/utils/blocks.test.js b/src/utils/blocks.test.js
index 984b2643e..d7f2ff60a 100644
--- a/src/utils/blocks.test.js
+++ b/src/utils/blocks.test.js
@@ -38,8 +38,8 @@ function assertBlockInserterPayloadShape( payload ) {
 	if ( validate( payload ) ) {
 		return;
 	}
-	const { instancePath, message } = validate.errors[ 0 ];
-	throw new Error( `${ instancePath || '/' }: ${ message }` );
+	const { instancePath, dataPath, message } = validate.errors[ 0 ];
+	throw new Error( `${ instancePath || dataPath || '/' }: ${ message }` );
 }
 
 function makeInserterItem( overrides = {} ) {