So, as in many things in life, there are three words of advice to follow: Keep it simple. All white is nice. All black can also work. A less formal but unifying look is jeans (and/or jean skirts) and white tops, be they T-shirts, blouses, or turtlenecks. In fact you can mix and match styles as long as the tops are a consistent color. You don’t have to use white, but if not the family should pick a neutral color that everyone has. That’s why white and black are easy colors.