I'm looking for a Little Golden Book from my childhood - possibly printed in the late 70's or early 80's. It was a Christmas story involving bears (I think) looking for a rainbow. The rainbow shattered and the bears used the pieces to decorate their Chistmas tree. Does anyone remember the title and author?

I think the story that you are looking for is "The Lights on the Christmas Tree" by Floence Page Jaques. I found it as the last story in a Little Golden Book called "My Christmas Treasury" My copy has a copyright date of 1976 and looks like it is a 5th edition. The price tag on the book is $0.89 and it has a number of 455-31. I don't know if the story is printed elsewhere or if it is in all copies of "My Christmas Treasury"

The story is about how the first christmas tree that Santa made was decorated with snowballs and iccles and he wanted some color on it. The littlest bear had the idea about the rainbow and convinced Santa to let him find it, however he tripped and broke the rainbow just as he was entering the house. Later they all discovered that the pieces of broken rainbow looked better than if it had been all in one piece. I hope that this helps.