Time and time again we've seen doors overlooked in design projects. The worst thing to find in a beautifully finished room is the builder's original slab door.
In these examples, doors are fully integrated in different ways. Some are upholstered or painted to fit into a color scheme, one is wallpapered seamlessly into its room, and still others are built into walls. Feel free to share your own ideas.
Images:
First Row:
1. Remodelista
2. Platinum Peony
3. this is a design blog
4. Country Living
5. How To: Give Character to a Drab Door
Second Row:
6. Neu Black
7. House and Home Designs
8. Furniture Fashion
9. Habitually Chic
10. Interior Designs for Homes
10 No-Fail Decor Tricks & Tips for Small Spaces
Beth's Romantic & Retro Residence
Good Food to Share 
The Big Book of Small, Cool Spaces 
Apartment Therapy Presents 
The Eight-Step Home Cure 
Shaw's Original Fir...
How to Cook Rice on the Stove
How To Cook Tender, Chewy Wheat Berries on the Stovetop
You know what's great about those yellow doors is not just the high lacquer color but the fact that they are super tall and lead into that marvelous library. Drool...
Agree. The yellow is perfect and I just love those rooms together.
In my first house, the painter was going to keep the back of the front door white, but I told him to use the same yellow he was using on the walls. He wasn't excited, but did it ... and was stunned by how good it looked.
I would love to know what color of yellow they used on the doors.