Women are having more fun with fashion in general—they're aware of trends and open to taking risks—and they're bringing that spirit to their weddings. You don't have to become someone else (read: more traditional than you are) for that one day. You don't even have to wear white! Bride Whitney, shown here, chose pink for herself and white for her 'maids.
It may be tempting to try to make your entire wedding party happy with their bridesmaid dress, but it's your day, and it's important to draw the line somewhere. If you want to take into account different body types do something like bride Traci did here: She chose the Amsale gown color and fabric she wanted her ladies to wear, but let them each choose the neckline they liked most. However, you can't abandon a dress if one of the girls doesn't like your color scheme.
Also, beware of allowing bridesmaids to wear any dress they want as long as it's in your chosen color. There are so many different interpretations of navy, brown, and burgundy that you can quickly lose control of how the group will look overall—so it's best to pass out a fabric swatch for them to match.
The simplest way to add color to your dress or a bridesmaid's ensemble is with a sash—Bride Anne chose a floral one for her bridesmaids here. I also like a hairpin or shoes in a soft shade as long as they don't compete with the gown. I'm not a fan of bright shoes for the bridal party—watching those come down the aisle is distracting.
You don't want your colors to contradict the feeling of the environment. If you're having an October wedding in Connecticut, hot pink might not make sense outdoors. You have a little more leeway indoors—you could use summery colors more easily in a ballroom in December than winter hues in a tent in mid-July.
If you don't have an eye for color, it can be tricky to tell which hues go together. That's when you should look at flowers—what different colors show up within a single pansy? What's the gradation of shades in a hydrangea? If it occurs in nature, it looks good.