How to choose a color scheme

When it comes to my bedroom, I love all things white.  White walls, white bedding...it reminds me of a spa, and I find that relaxing.  Recently though, I've found it fairly boring and uninspiring and I'm thinking of spicing up my desk chair and making a headboard to add a splash of color.  So, my quest this weekend is to pick out some fabric for each project.  My problem however, is that I cannot decide on a color scheme.  Hopefully these basic design principles will guide me to the perfect color combo:

Choose a color scheme from the biggest pattern in your space- For me, my huge Matisse poster from the Tate Modern is the largest pattern in my bedroom.  Unfortunately, it doesn't narrow down my choices much since it consists of white, black, purple, red, gold, orange, blue and green.

Copy Mother Nature- A space seems balanced when the floor is the darkest color (earth), the walls are a mid shade (trees and buildings), and the ceiling is the lightest color (sky)

Check your closet- Chances are you wear colors that look good on you.  If you don't wear yellow, don't buy the yellow bedspread.

60-30-10- Choose one color to take up 60% of your room (typically wall color), another for 30% and a 10% accent color (I'm still searching for my 30% and 10%...obviously my 60% is white)

Go with the Architecture- Don't make a small room something it's not.  If a room is small, make it cozy and intimate, don't fight a losing battle using white paint and minimalist furniture to make it appear larger.

Here are some photos that are offer inspiring color schemes...what do you suggest I should do (I'm thinking white, gray, and yellow)?

Happy Friday!