How to change color background

[Quangninh-io]

How to change background color, I try to change color at ImageGLSurfaceView in
@Override public void onSurfaceChanged(GL10 gl, int width, int height) { GLES20.glClearColor(1.0f, 1.0f, 1.0f, 1.0f); mViewWidth = width; mViewHeight = height; calcViewport(); }
but it doesn't work the background is always black