If you're looking for a casual and at the same time seriously stylish look, consider pairing a navy long sleeve shirt with navy jeans. To bring out the fun side of you, complete your getup with a pair of work boots. As you can see here, even in your fifties you still have a wide range of dressing options.
Reach for a navy long sleeve shirt and brown corduroy chinos for an off-duty look with a contemporary spin. With footwear, go for something on the relaxed end of the spectrum and complete this outfit with work boots. And if we're talking casual style for guys in their 50s, this combination looks good on almost any gentleman.