Mother of the Bride and Groom Dress Colour?
It is acceptable for the Mother of the Bride/Groom to wear an outfit in a colour that fits the bridal party theme. It shouldn't be the same colour as the bridesmaids, however it can fit with the theme. If you have a pastels theme, then your mother can wear something in that range to compliment the bridal party in photos, and during the event. The father of the bride/groom can either wear a tie the suit his partner's outfit, or the bridal party colours. This will work if he is also getting a button hole flower. And remember, most importantly, no white, ivory or champagne, even if the bride is wearing a wedding dress in a colour other than white. You don't want to show up the bride as it is her day.