Rainbow ran on ITV for 20 years, mostly at lunchtimes. It became one of the highest rating children's shows of all time and one of most enduringly popular.
After over 1500 shows, Rainbow came to an end in 1992, but the show remains a massive success with people of all ages. 

(Please note, it is impossible to trace information on all of the 1500+ episodes produced but a large number, mostly which were released on various videos, are listed here.)