To look nice and sharp, consider pairing a purple waistcoat with a white and navy vertical striped dress shirt. Take an otherwise sober getup down a more casual path by rounding off with a pair of navy and white athletic shoes. When leaves turn yellow and red and fall is in full swing, you'll love this outfit as your favorite for in-between weather. This pairing is a vivid example men in their 40s can very well kill in the fashion department.