Wearing the same color makes you looks proportionally taller and skinnier, because you are not "chopped" by colors. However, when you want to wear the same color, makes sure you wear it in different shade to show a bit of layering and differences. On me today, I chose to wear grey. so i had a darker grey swearter, pairing with light grey pants and a lighter shade of grey for the jacket. White and black are also shades of grey too, therefore i had a black beanie on to put some weight into the whole look, and white sneakers for some pop of color. Another way of making a same color outfit more interesting is by adding some fun details, such as what i have on the bag: fringe.