I much prefer a dark trench—like this nylon specimen from J. Crew—to a khaki one. They just seem more sophisticated in a Euro way to me.
But go figure, I do like the khaki on this Barbour rain jacket; that link will send you to extended sizes; click here for the rest.
These water-resistant pants have a comfy elastic waist but otherwise look like a snappy pair of trousers. Perfect for anyone with morning yoga or dog-walking responsibilities.
I find it mostly impossible to put on rain boots—twice I’ve busted the tab trying vainly to get them on—so I appreciate this zip-up pair. I also think the zipper is a cool detail.
And here’s a pair of waterproof sneaks with a nice platform-ish heel.
A rain hat from Barbour that reminds me of these pricier ones from Stutterheim.
A happy, loud umbrella can be just the ticket on a gray, rainy day. Also, I used to own and love this one from Marimekko, which is perfectly small enough to fit in your bag, but then perfectly big enough to keep you dry when it starts coming down. Only problem is they raised the price to $70, and I can’t see spending that on something I will surely lose. 
A sweet water-resistant crossbody tote that comes in several other cute colorways.
I recently purchased the ShortyLove backpack and I LOVE it. Fits my laptop, has all the right pockets and is very stylish.
I love the crossbody. I will check the website for the backpack.
Yes to the rain hat! I converted during lockdown, so much easier than an umbrella. I own 3-a lined one for colder days, and 2 lighter weight ones for warmer days. I recommend this one from LLbean https://www.llbean.com/llb/shop/120027?attrValue_0=+Color+Option:+Dark+Rose,+$44.95.&qs=3080290_TnL5HPStwNw-bj.AbVn3qJmKCKCH7rcCSQ&cvosrc=affiliate.linkshare.TnL5HPStwNw
I live in the outdoor voices RecTrek pant. Have not tested in the rain though so can’t speak to water resistance but they are so versatile and comfy. Around the house, hiking, errands, office, travel. All that changes are the shoes and tops.
Here to second a high recommendation to the RecTrek pants. Bought them a couple of months ago and love them––particularly for walking the dog, but also bought them thinking they’d be good travel pants––and they will be as they are super comfortable, don’t wrinkle or bag out at the knees and look crisp and put together even if you’ve worn them all day long. Just listened to the newest EIF podcast (no interview came through, but will assume y’all will get that worked out later) and wanted to throw in my two cents regarding wedding reception photos: Have a professional photographer for before the ceremony and whatever photos you want after, then, for the reception hand out either disposable cameras (not great for the environment, but…) or instant cameras (better for the environment, but more expensive). I’ve been to weddings and birthdays that have featured one or the other and they are great ice breakers, get people interacting and participating and can produce some pretty wonderful photos to keep and share. In any case I hope you have a wonderful just-like-y’all-want-it wedding and hope there is a podcast that gives us all an in depth description of your fabulous day.
I am forever haunted by something I read somewhere–a fashion mag? A how to dress book?–that said dark trenches are more practical but lighter beige ones are more sophisticated and classier because you’re showing that you can afford the dry-cleaning bills. It lives rent-free in my head, as the kids say. I only have denim and army green trenches but I still feel guilty about not buying a beige one–but it’s true, they get grimy! Especially in the city!
I think you’re right about the slightly more sophisticated trench in a dark shade (Of course! You’re Kim France!) . I’ve noticed the trend on Instagram.
Best wishes on your upcoming wedding. Enjoy your day!