Breathe variety into your current casual wardrobe with an olive military jacket and navy chinos. For a more polished touch, why not round off with black leather derby shoes? This combo demonstrates that well into your 40s you still have a wide range of styling options.
To look like a refined gentleman with a good deal of style, try pairing an olive military jacket with dark brown dress pants. Black leather derby shoes are a nice choice to finish your getup. Surely a foolproof option if we're talking dressing ideas for 40-year-old gentlemen.