Go for it!
I wouldn’t have said metallic looking, so much as grey.
Charlie used the word silver because he knows Flower will think it sounds impressive. Also, he’s a fluffy and so can’t really make that much of a distinction.
That being said, I’m not going to be too precious about it, especially if it’s not a paid commission.
The only real description I’ve given of Silver so far is here Nightmare at 70mph. By Poopieplace and that’s not massively detailed either. He’s a unicorn, his eyes are green and at some point he will get a scar.