Thanks all. That's what I was worried about and you've confirmed it! It's actually grey (they do a black version too) but perhaps that shade of grey is so dark that it may as well be black. Maybe I'll keep it anyway and wear it for something else
The wedding's not til May (but NW of England hence the need to find a jacket too) so I have a while.
I like it. Thin silver belt to match shoes and a bright jacket and it'll be perfect. I've got no time for wedding guest attire rules, as long as you don't wear white you should be fine. I've worn black to the last two weddings I've been to and no-one has been upset or shunned me or thrown canapés at me or had me burned as a witch.
I think it would be absolutely fine for a wedding. Glam it up with a chunky necklace, different belt and glittery heels and it would be lovely. Agree with ephemeralfairy, in that I have no time for wedding attire rules and am not into dresses that look too wedding guest like.
I think it's too casual, sorry. It's nice, but it isn't wedding attire. It's the fabric. You wouldn't actually look inappropriate- no-one could be offended by it- but you could do better. And personally I think a dress and jacket combo is a bit "worky" for a wedding.