When picking out a look for your wedding makeup remember to think big picture! If your bridesmaids are wearing a soft pastel color you want your makeup to look good with that color. All of the girls should compliment the whole. Adding brown or gold to a soft blue/gray palette can look harsh in photos.
When your dresses are light and airy you want to makeup to work with the look of the dress - not over power them. Summer weddings are great for softer makeup looks with the lighter fabric and colors.
Your trial is a great time to experiment with different colors and looks and your professional makeup artist can guide you as to what will best compliment the whole look!