The Muppets were treated nicely by their composers from WILLIAMS, RAPOSO, BURNS and the later ones from the 90's. All had a nice diversity of music and songs, from the catchy, the fast to the beautiful and the pretty.
Are there really that many songs about rainbows? I can think of only two.
Here are a few.....
THERE'S A RAINBOW 'ROUND MY SHOULDER (Al Jolson-Dave Dreyer-Billy Rose).....ca.1928 RAINBOW ON THE RIVER (Louis Alter-Paul Francis Webster).....ca.1936 WHERE'S THAT RAINBOW? (Richard Rodgers-Lorenz Hart).....ca.1927 RAINBOWS, POTS OF GOLD & MOONBEAMS (Steve Cooley).....ca.1975 I CAN SING A RAINBOW (Arthur Hamilton).....ca.1955