I've been invited to a wedding (in Scotland, UK). It's described as a "Black-tie" event and the groom has asked guests to wear a dinner jacket (tuxedo), but it's not an absolute requirement. A few guests will be wearing suits, and I plan to do the same.

For guests wearing a dinner jacket, they will be wearing black bow ties, which is the expected accompaniment.

My question is: is there etiquette about what colour and type of tie to wear when attending a "black tie" but not actually wearing a dinner jacket?

Should the tie be a bow tie? (That may look a bit half-baked.)

Should the tie also be black? (That may look like I am attending a funeral, which is something I'd want to avoid unless it's the expected look, but it would match the general colour theme.)

Or is there no expected standard and I can wear whatever colour tie I like?