1. Grownup taste can appeal to kids. "I wanted Bumble's interiors to reflect what we are: a sanctuary where adults can relax and a place where kids feel welcome," says Heffernan. Interior designer Christian Brennan helped Heffernan refine her gray, yellow, white, and black color palette, which reflects — you guessed it — a bumblebee theme.Scared of incorporating gray into your home? Interior designer Martha O'Hara says gray doesn't have to mean austere. "When used correctly, cool tones like gray and silver can be inviting and comfortable," she explains. Add a modern splash of yellow for a living room that's a fun take on traditional and friendly to young and old alike.