WebGLColorBuffer: reset currentColorClear without creating new Vector4 (#9543)

src/renderers/webgl/WebGLState.js

@@ -683,7 +683,7 @@ function WebGLColorBuffer( gl, state ) {
 		locked = false;
 
 		currentColorMask = null;
-		currentColorClear = new Vector4();
+		currentColorClear.set(0, 0, 0, 1);
 
 	};