Fix clear color bug

src/renderers/webgl/WebGLState.js

@@ -13,7 +13,7 @@ function WebGLState( gl, extensions, paramThreeToGL ) {
 
 		var color = new Vector4();
 		var currentColorMask = null;
-		var currentColorClear = new Vector4();
+		var currentColorClear = new Vector4( 0, 0, 0, 0 );
 
 		return {
 
@@ -58,7 +58,7 @@ function WebGLState( gl, extensions, paramThreeToGL ) {
 				locked = false;
 
 				currentColorMask = null;
-				currentColorClear.set( 0, 0, 0, 1 );
+				currentColorClear.set( - 1, 0, 0, 0 );
 
 			}