April is definitely time for spring colors. Brown would be too drab, BUT that one has pink and little flowers on it. New life born of the earth and all that. The totally red dress is far too ostentatious to be polite at someone else's wedding, so I'd say your best choice is to go with number two, number three in my opinion looks like a little goth prom dress. Plus, the brown would look awesome with your hair and show off the line of your collarbone and shoulders. :)