Groom Attire

I have a question. So my colors for the wedding are like a dusty blue, and gold. My fiance only cared about one thing, and said he trusted my gut on everything else, that he got to wear blue because it's his favorite color. I was wondering if it was weird for him to have a blue vest and tie, and all the groomsmen have just a blue tie. The suits are all going to be grey. I was told that my FH, if he wants color should only have a blue tie and then wear a white vest, I've also been told that he's supposed to wear all white under the suit. I just don't know. lol.