For something more on the casually cool end, consider teaming a grey blazer with white jeans. You could perhaps get a bit experimental in the footwear department and complete this ensemble with a pair of grey athletic shoes.
Grey Blazer with Grey Athletic Shoes Smart Casual Outfits For Men
A grey blazer and grey cargo pants are the perfect way to introduce extra cool into your off-duty routine. Finish this outfit with grey athletic shoes to switch things up.