If I have to choose a monochrome look ( which I often do) I always make sure to add contrasting pops of colours( but you already know that as well). So once again I have an example to showcase this theory: grey shirt and shorts and a bright pair of espadrilles. Voila! After rain always comes the sun!
SHIRT: vintage, option Here, Here and Here / SHORTS: 3.1 Phillip Lim, similar Here and Here / BAG: Fendi Here and Here / SNEAKERS: Asos Here and options Here Here and Here / NECKLACE: c/o K-Kane Here / BRACELET: c/o K-Kane Here /SUNGLASSES: Ralph Lauren Here