Black is a figure flattering colour, I think it would be okay, plus there will be many other people wearing black as well. The representation of the colour does not reflect the emotions anymore (if that makes sense) its just a colour that looks great on people.
Several people wore black to our wedding. I guess it's ok but I would have liked more colour. The mother of the groom could wear dark blue which also looks stunning with silver accessories. I guess I'm not a fan of black for weddings.
The groomsmen and my FH will be wearing all black with coloured flowers matching the bridesmaids they are matched with. Black seems to be a common colour these days. Thanks for sharing about the colour red in Sweden never knew that.
I say wear whatever you will be comfortable in and not have regrets with when looking back at photos. There are so many traditions nowadays, so unless the couple has set a specific dress code I say go for it!