Why not team a grey denim shirt with red shorts? These two items are super practical and will look great matched together. When in doubt about what to wear on the shoe front, go with a pair of slip-on sneakers.
Grey Denim Shirt with Slip-on Sneakers Outfits For Men
If you love off-duty pairings, then you'll appreciate this pairing of a grey denim shirt and black chinos. On the footwear front, this outfit is completed really well with slip-on sneakers.
A grey denim shirt and dark green chinos are a nice combo that will easily carry you throughout the day. Introduce a pair of slip-on sneakers to the equation and the whole ensemble will come together wonderfully.