The phrase "grey suit" refers to a traditional business outfit typically worn by professionals or office workers. It usually consists of a matching jacket and pants in the color grey. Full definition
Layer beneath a dark grey suit and finish your look with black sneakers for a contemporary tailored outfit. (reiss.com)
Her brilliant ability to explain finance in a simple way and her bright purple shoes make her stand out from the crowd of grey suits. (totalpolitics.com)
Try wearing a lighter grey suit jacket and trousers with a simple white tee underneath. (theidleman.com)