Kat, the Orchid is such a wonderful house! There are so many possibilities. Hannah chose her color combination to match a pillow she had just quilted because she loved the color combination so much. My sister was apprehensive about how it would work out, but it's just great! For my houses, I go to the paint store and get a number of color swatches I like. I cut out rectangles to represent the window frames and put them over the house color so I get a feel for how they will look together. Same thing with the contrasting colors. I make thin strips and attach them where the trim would be. That way, I have all of my colors together represented in the way I would see them.
I use Behr interior paint. I buy a quart of the main color in satin, and buy the trim colors in the sample sizes which only come in eggshell.
I can't wait to see your Orchid as it comes together!