Black tie - what to wear?

Happy Wednesday everyone! Hope your week is treating you well so far. I'm organising an event for work and because I'm a sucker for gowns/maxi dresses I suggested (very strongly to the bosses) that we make it a black tie event. Black tie is a dress code for events that starts after 6pm and basically says "fancy evening party". Men should wear tuxedos and women cocktail/gown dresses. Now that the dress code has been confirmed (yay!) I am on the hunt for a nice and elegant maxi dress. I could wear a midi dress but I can wear that any day of the year and floor lenght is just a little fancier, don't you think?

On to the dress I am looking for. It has to be floor length (not hard as I'm of the petite range), not too booby/leggy as it is a work event, elegant and minimal. Here's a few options:

Pastel colours. So. Incredibly. Colourful. I like the off shoulder style and the one with thin straps!

 Again, lots of thin straps. I've actually ordered one of these to try.. can you guess which one?

And my fave collage, haha. Black <3 The wrap dress is a classic that I could wear plenty of times after. I love a good long sleeve dress and the back of that one is beautiful!

I have 6 dresses being delivered today to try.. I'll try and take a pictures of me wearing them and you can help me decide, deal?!

Dresses from Jarlo, Asos, Ax paris, Selected, Stylestalker, Vlabel and Little Mistress Adlinks in the collages