Mixed Gender Bridal Party Fashion

If you are only planning on matching accessories, such as pocket squares or ties, Azazie is an option. It is a Canadian website. They have bridesmaids dresses and corresponding accessories for groomsmen.

They offer a try on program for dresses and also make dresses custom to your measurements.

My Fiancé is having a groomswoman. This groomsmen are wearing grey suits so we are trying to find a grey close to it for her dress.
A friend of mine has a bridesman and he wore the same colour suit as the groomsmen and matched his tie/pocket square to the bridesmaid dresses

It really depends on the colour and whether you want it to be 100% exact. I personally don't care for matching 100% exactly but I know a lot of brides do and trying to get a full suit to match the exact shade of a bridesmaid dress won't be easy (no one carries a bunch of blush suits on hand because it won't sell). Typically when couples are looking to match their bridal party, they do so via the men's accessories, which are much easier to find.

Also, suits that are not part of the traditional slate (grey, charcoal, blue, navy) will either be really expensive (likely made to measure from a custom fabric) or really bad quality.