Reload/refresh Live WallPaper

[MOST2K2]

Hello, i want to have a custom background in my live wallpaper (i use a plane for that and it works already).
In preference screen i have added a preference to choose the color.
how can i reload/refresh the engine/renderer to apply the new color?

The new color will be used when i remove the wallpaper and set it again.
I have tried the following:

public void reset()
{
// stopRendering();
mTextureManager.reset();
mMaterialManager.reset();
// clearScenes();

mSceneInitialized = false;

}

(this method is called when SettingsPreferenceActivity.onCreate is called)

Edit: I read the preferences in initScene of the Renderer.

Thanks for help!