Changed SV bg color to match editor default bg color (when gradient is off and square alpha is 0).

spine-libgdx/spine-skeletonviewer/src/com/esotericsoftware/spine/SkeletonViewer.java

@@ -253,7 +253,7 @@ public class SkeletonViewer extends ApplicationAdapter {
 	}
 
 	public void render () {
-		Gdx.gl.glClearColor(0.3f, 0.3f, 0.3f, 1);
+		Gdx.gl.glClearColor(112 / 255f, 111 / 255f, 118 / 255f, 1);
 		Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);
 
 		float delta = Gdx.graphics.getDeltaTime();