A beige long sleeve shirt and white shorts are great menswear staples that will integrate perfectly within your casual repertoire. To give this ensemble a classier twist, why not complement your look with brown suede loafers? After 30, you want to start dressing maturely. If that's the case, getups like this are a surefire option.
This refined combination of a beige long sleeve shirt and white dress pants will allow you to flex your outfit coordination skills. A pair of brown suede loafers is a savvy idea to finish off this ensemble. This combo is most probably what you're looking for as a gent in his thirties.
Pair a beige long sleeve shirt with white chinos if you want to look casually stylish without too much effort. A pair of brown suede loafers immediately amps up the style factor of any getup. This is a nice and mature ensemble for 30-year-old gents.