Why not pair a green-yellow turtleneck with charcoal chinos? As well as totally practical, both of these pieces look good married together. Get a bit experimental in the shoe department and add athletic shoes to the mix.
Green-Yellow Turtleneck with Athletic Shoes Smart Casual Warm Weather Outfits For Men
A green-yellow turtleneck and white chinos will give off this relaxed and dapper vibe. A pair of athletic shoes will add more character to an otherwise dressy look.