German wedding question--what should we wear?

Mr. Scribble and I are going to a German Catholic wedding on Sunday. It will be held (deleted personal information) near (deleted).

The groom told us that Mr. Scribble would be OK with a suit jacket and pants (no need for a full suit).

The wedding’s in a cathedral, and there’s going to be a traditional Catholic ceremony. The bride’s family, from what I understand, are kind of conservative, culturally and religiously. As far as we can tell, this is going to be a more-or-less traditional wedding.

So, here are our questions:

  1. Can we wear black in any form?

  2. Can Mr. Scribble wear some black (say, black pants) if the rest of his clothing is non-black?

  3. Can I wear anything black? I have a very nice pair of black dress slacks that I was thinking of pairing with a somewhat dressy silver silk blouse. Would this be OK, or is black a definite no-no?

  4. Could he or I wear red and not be inappropriate?

We bought the couple a nice Chinese-style ceramic vase, but we’d like other ideas for more creative wedding gifts. (We really didn’t know what to get them. The groom is a colleague of Mr. Scribble’s. Mr. Scribble likes the guy, but he doesn’t really know what he’d want or need, other than a bunch of rather expensive and difficult-to-transport items on this list of gifts the groom’s parents suggested.) We’d like something that we can get quickly, that doesn’t cost a fortune, and that the new couple might enjoy more than a vase.

We’d appreciate any help you could offer. Thanks a bunch!

Umm…it occurred to Mr. Scribble and me that some of the info in my OP is rather specific. We don’t think the groom reads the SDMB, but you never know. (The groom is a pretty cool guy, and he’d probably like this place. ) In any case, we’d really a mod to delete the OP if possible. Thanks a bunch, sorry for the inconvenience.