My sisters and I had some professional photos taken. We had none of the three of us since.... hm, forever.
Matching coloured papers to this one was amazingly difficult. If I picked the blues and purple tones from the photo, we looked like Smurfs and if I went with the brown and olive tones of the meadow we looked washed out. So instead I took a contrasting background colour (choc brown) and picked papers with a similar hue and saturation. Like the colours in the photo, these are bright colors, but not primaries. Then I offset it with skyblue to brighten it all up. Note that none of the papers match an exact colour in the photo, but rather compliment them and bring them out.
Don't be afraid to pick colours to suit the "mood" in your photo, rather than the colours!
Add a bunch of butterflies and a few small scatterings of embellies and you're done!