You're looking at the hard proof that a dark brown blazer and a dress shirt look amazing together in a classy look for a modern guy. As you're going from your 20s to your 30s, you want to start dressing in a dressier manner. If that's the case, looks like this are perfect as inspiration.
Dark Brown Blazer with Dress Shirt Dressy Chill Weather Outfits For Men In Their 20s
For a look that's truly envy-worthy, consider wearing a dark brown blazer and a dress shirt. Introduce a pair of dark brown leather brogues to the mix et voila, the outfit is complete. Certainly, an amazing example of grown-up fashion.