Sock Yarn for men

I hope this is the right place for this question, but if not, could the moderator please move and let me know? Thanks!

I am just starting to learn how to knit socks. My brother is wanting a pair as well. I said no, because it will take me forever to finish mine! Anyway, I had hoped to maybe get a pair in as a surprise for Christmas.

Can anyone help me find some yarn that would be suitable for a man without it seeming feminine? Or am I to only use a solid color?

Just curious?
Thanks so much in advance.

Welcome to KH!
Here are some ideas for types of yarn and colors.

The tab at the top shows different yarns used and the projects link tab (or to the right) shows yarns and colors that have been used.
They need not be a single color but are you sure your brother wouldn’t like a wild and crazy pattern?