This is a representation of a journey through the time tunnel. You are overcome by time, surrounded by its pathways, and there is no escape.
The sands of time literally bury our hero in the next shot,and he is unable to escape this trap. Then, the series title comes up, backwards at first (as though we are viewing it from the inside of the hour glass).
Below, you can see the colorful Time Tunnel montage in live action.