A mustard print short sleeve shirt and mustard sweatpants are a bold casual pairing that every modern guy should have in his casual wardrobe. Feeling inventive today? Change things up a bit by sporting a pair of white canvas low top sneakers. This ensemble isn't a hard one to achieve and it's summer-friendly, which is most important when it's baking hot outside. Relaxed looks for gents in their thirties aren't actually that hard, as you can see.