Picture frames make fantastic decoration around the home as they add style and personality, taking you to a trip down memory lane with your photos whilst intriguing visitors (photos make good conversation starters).
Picture frames, I believe, need to suit the mood of the photo(s) you plan to put in them; for instance, a block bright red photo frame would not entirely suit a black and white mellow picture, it would contrast too much the emotion of the photo.
Playing with colour is fun and creative, but smetimes it may be appropriate to keep it toned down. I find that a black frame will go with anything, and so the frame can be used anywhere around the house should you feel to reshuffle your decor :)
These are my favourite style for photo frames because they are so pretty and decorative.