In this case, you can choose a light blue or violet shirt, and a tie can be paired with burgundy or deep purple. These two colors match well, and your gray suit is very handsome.

I bought him two pieces on my friend's wedding website, one is purple and the other is sky blue (with a black suit). After receiving it, I said I liked it very much, and the quality was the same as that of the counter. You can go and have a look if you are interested. A large shopping website searches for shops: Aishang Dongdong is it. I hope my answer will satisfy you.