A navy and green long sleeve shirt and blue jeans make for the ultimate casual ensemble for any modern guy. For maximum style effect, complement this ensemble with desert boots. This combination is probably exactly what you're looking for as a gent in his 50s.
A navy and green long sleeve shirt and olive corduroy chinos make for the perfect base for a casually stylish ensemble. A pair of desert boots is a wonderful option to round off your ensemble. An excellent option for a gent in his fifties!
If you'd like take your casual look up a notch, dress in a navy and green long sleeve shirt and khaki chinos. If in doubt as to what to wear on the shoe front, go with desert boots. An obvious option for a mature guy!