You will find your answer in Metallica’s song, “Back in Rainbow”.
Who knew then that one of England’s finest, Tolkien was a vile racist? By the Ba ba Logic the Lord of the Rings is going to have to be completely re-written.
Rainbow Riders
The terrible Rainbow Hand of Sauron
Mordor - the Rainbow Land
Although, I must say this creates a bit of a conflict and will do a lot of harm to the overall plot.