This is irrefutable proof that a blue dress shirt and charcoal dress pants are amazing when paired together in a classy ensemble for today's gentleman. To give your overall getup a more laid-back aesthetic, add a pair of black leather derby shoes to the equation. Naturally, it's easier to work through a roasting hot hot weather day in a fresh combination like this one. No doubt, a fail-safe option when it comes to outfit ideas for 40-year-old guys.