At some point, most likely earlier rather then later, you will need to pick your wedding colors. If you just like color in general, it can be very hard to narrow it down. At one point it couldn't be more then 3, 4, or 5 different colors! But what if you can't decide?
Rainbow! What a great way to go. If you think it would be overwhelming or just too much, there are many tasteful ways of doing this. You can use a base color of black or white and use rainbow colors as the added pop of color. Your bridesmaids could each be one of the colors for their dresses, their bouquets could have the neutral base color and your bouquet could have the rainbow effect. Maybe you'll even splurge on yourself and get rainbow roses! Your center pieces could be on plain white table cloths, and they would have a rainbow of flowers or candy. Your desserts can have rainbow colors, you could arrange them so they move from one color to the next, instead of a random mass of colors thrown together. Let your imagination run wild!
Here is a great Rainbow wedding: http://www.rocknrollbride.com/2012/04/the-rainbow-wedding-to-end-all-rainbow-weddings-jen-ben/#more-112908
If you want more examples of rainbow weddings you can search for them on these great websites:
Rock n Roll Bride