Whose wedding is it? Yours or Mother's? From what you've said so far, this wedding is not so much a celebration of you and your FH as it is an event for Mother to show off and keep up appearances. I'm not trying to be mean, but it really feels like your wedding is going to be lacking a lot of YOU and of your FH... and really be about what Mother wants.
Honestly? She'd toss someone out of the church for having the audacity to wear the wedding colors? You're going to have to go with some pretty funky unusual colors to pull that one off. Like.... Dayglow Orange with Metallic Green Accents.