The living room below is so ecelectic, it features the 3 primary colors and I really love it! The room is bold and artistic, it's a melting pot of many styles but it works well; and you gotta love the classic Eames Lounge Chair by Herman Miller featured in the space. I hope you'll forgive me that the blue in the room is not a really a primary colored blue, but I couldn't pass the opportunity to share this space with you.
Finally there is the split-complementary color scheme which takes one color, and the colors on both sides of it's complement.
Below is a bedroom that also borrowed from the color wheel's triadic theory for it's scheme, using primary colors as well.
This cozy little hide away below uses red, yellow-green, and blue-green in it's split complmentary scheme.