The phrase ‘coat of many colours’ originated in the Bible, Genesis 37:3 (King James Version):
Now Israel loved Joseph more than all his children, because he was the son of his old age: and he made him a coat of many colours.
Genesis 37:23:
And it came to pass, when Joseph was come unto his brethren, that they stript Joseph out of his coat, his coat of many colours that was on him;
Genesis 37:32:
And they sent the coat of many colours, and they brought it to their father; and said, This have we found: know now whether it be thy son’s coat or no.
The expression ‘coat of many colours’ was the source of the text of the 1960s musical Joseph and his Amazing Tecnicolour Dreamcoat, with lyrics by Tim Rice and music by Andrew Lloyd Webber