I would have to ask a few questions in order to answer appropriately.
What colors are being used in the ceremony/reception? What colors and textures are the dresses?
Will you be inside or outside and also what time is the ceremony? (Different lighting throughout the day will make your makeup look different)
It is important to choose colors that will look good on everyone and unless you use something neutral- that could be difficult. Choosing an eyeshadow for all skin tones ranging from fair-dark is a job in itself.
Another factor to take into consideration would be choosing a shadow with a matte finish, shimmer or sparkle. This is important, as shimmer and shadows with sparkles/glitter act as a magnifying glass on the skin making fine lines and wrinkles much more apparent. So, if you have anyone in the bridal party that may be more mature I would suggest using matte shadows as they will look good on everyone.
Some of the "safer" colors to choose would be matte chocolate brown, matte golden brown, Khaki, Cream color.... All are options that could work on a majority of skin tones as well.
However, taking the questions I listed above may help you choose not only colors that work for different skin tones but also colors that will fit with the look and feel of the wedding!
Good Luck!

bridesmaid? all skin tones? i'd say shimmery gold and purple. why don't you pick 3 of your friends/family with different skin tones and give it a try prior to the wedding. :) Good luck!! Post some pics here if u can!! we'd love to see!

I think browns/golds/light greens are pretty flattering on most complexions.

would say white or a grayish slver color.