Consider pairing a navy overcoat with navy vertical striped dress pants if you're going for a proper, dapper outfit. Brown leather oxford shoes are a nice option to round off your outfit. Seriously stylish, this pairing is also totally age-appropriate.
You're looking at the indisputable proof that a navy overcoat and black and white houndstooth dress pants look awesome when married together in a sophisticated ensemble for today's gentleman. Complement this ensemble with brown leather oxford shoes and off you go looking smashing. This combo illustrates that as a 40-year-old gentleman, you have a wide array of sartorial options.