1. A computer-implemented method, comprising: determining an object in a graphical user interface (GUI) rendered by a remote server and displayed on a client device based on display information transmitted from the remote server to the client device over a network, wherein the object is manipulated by the server in response to one or more input events; selecting a portion of the GUI displayed on the client device that includes at least some background around the object; sampling colors of a set of points in the selected portion of GUI by the client device; determining whether the object has been updated by a frame update based at least in part on the sampled colors of the set of points in the selected portion of the GUI.