Lenwë and Sarumans ring.

[Finwe]

That's right. And also, he was tired of going by the rules of the Order, with each person having his own, one color. He wanted to show that he was greater than all of them, that his powers encompassed all colors. I think that what the colors actually meant was the powers or the personalities of the wearers.

For example, Gandalf's color was Grey (originally). He always walked in "disguise," in a way. If you looked at him, you wouldn't be able to tell if he was a wizard or just another old man with a strange color-fetish. On the other hand, white is very obvious color. It stands out for miles. Saruman had the type of personality that would stand out for miles. Once you looked at him, even if he wasn't wearing his terribly conspicuous white robes, you could tell that he wasn't ordinary. For Radagast, brown represented the Earth. He loved the Earth and its animals, therefore, he had that color. Alatar and Pallando both had blue, which I assume has something to do with air. Air is the ultimate wanderer, it never sits in one place for long. I imagine that Alatar and Pallando were both like that, wanderers at heart. But I do wonder whether Oromë had a secret agenda to fulfil by sending them. He loved the Elves in the far East, where they woke up. He probably sent them to check on Cuivienen in the East, which is why, all we know about them is that they went East, and were never heard from again. Of course, that is pure speculation, don't take my word for anything.