Brown mother of the groom dress, is it appropriate?

My son is getting married next weekend. I have been shopping adnauseum for an appropriate dress. My husband has to wear a tux (yellow vest and tie). It is at 5p. The only dress I have found that is knee length (it is an outdoor wedding) is brown. It is a pretty dress with about a 1 inch ribbon sash with an attached bow under the bodice and it has a bolero jacket with beading. So it is pretty, however, brown has historically not been my favorite color. I am fair and look better in pastels. Plus brown does not seem an appropriate color for spring/summer. I was desperate to find something that looked nice and fit me. Is brown going to be okay to wear this time of year? If it was fall I wouldn't even need to ask, but I feel like I am going to look stupid. Any thoughts?