When matching colors to go with your wedding theme, try to choose one bright strong color, and add two to three soft pastel colors that match. Weather you choose a more vintage wedding theme or something more adventurous like candy land, try not to choose too many colors, even if they match they can clash.
For a vintage wedding try colors that are more toned down, like a faded rose and an ivory cream to match. For a more elegant wedding you could even go for the less is more option, for example, choose only shades of white with one color that pops, like Gold. If you are a doing a themed wedding such as beach, then my advise is to get a photograph that inspires you and choose one bright color that draws your eye and compliment that color with creams and pastels. Just remember, the beauty in is the detail.
So here is a color pallet chart that will get you started: