- The Lord of the Rings - The Fellowship of the Rings: The Council of ElrondFor I am Saruman the Wise, Saruman Ring-maker, Saruman of Many
Colours!āā
āI looked then and saw that his robes, which had seemed white,
were not so, but were woven of all colours, and if he moved they
shimmered and changed hue so that the eye was bewildered.
The Coat of Many Colours (wikipedia)
- King James Version, Genesis 37:3Now 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."
As a devote Catholic Tolkien must have been aware of the Biblical Coat of Many Colors, and this is not a particularly common phrase. One knock against this theory is not every translation Tolkien was likely to have read use that phrasing. Wycliffe does, Douai-Rheims used "divers" instead.
The coat of many colors represents favoritism, leadership, and being chosen as the heir, but it is important to note it was handed down by an authority. I assume the main symbolism here is that Saruman is forging his own Coat of Many Colors. He is saying he is the favorite, he is demanding leadership. This is in juxtaposition to the rightful handing down of authority as shown in the Genesis 37.
To Saruman, the many colors clearly symbolized him taking over the leadership role in his relationship to Sauron and the world in general and becoming the favorite of Morgoth.

