Opt for a dark green crew-neck sweater and navy dress pants to look like a British gent at all times. A pair of white canvas low top sneakers will add a mellow feel to this outfit. As a 30-something Millennial gent, you want to start dressing maturely. That's when inspo like this comes in handy.
If the situation allows laid-back dressing, pair a dark green crew-neck sweater with charcoal chinos. You can get a little creative with shoes and complete your look with white canvas low top sneakers. A safe bet for 30-something Millennial gentlemen looking for a more mature image.