I had a movie when I was younger (probably an 90s movie). It was a kids cartoon and I’m pretty sure it was a sing along. All I remember is this boy and girl go to another world and they’re gliding down a rainbow. I’m pretty sure the boy had blonde hair. I know it was English, and made in the US. Not by Disney though. (Not My Little Pony or Care Bears)
How about, Rainbow Brite?
No, it wasn’t a very well known cartoon.