Wedding outfit advice

[Quattrocento]

I need to get something to wear for a wedding, and would love some assistance from MN style gurus.

Basic requirements are:

1. Needs to be purchasable online as due to general disorganisation (wedding next weekend) have no time to shop
2. Should really be fitted - am a size 8 and long and thin. Anything floaty makes me look like a beanpole. Anything with too much fabric or fuller fitted makes me look like a flagpole.
3. Can't wear red/orange. Prefer not to wear white or black at a wedding.
4. Won't wear a maxi dress
5. Prefer not to reveal knobbly knees, so just below knee-length best

Please help!

If the budget will stretch to it, Hobbs have some lovely shift dresses which would be great for your figure.

I like this spotty one and this green one.

This navy one is lovely

Oh thank you! That green one is lovely! What do I do with the backless bit? I tend to need a bit of support at the front IYSWIM. Are there backless bras?

plum LK Bennett in the sale?

Bravissimo have a bra converter kit which might do the trick on a bra you already have?

You're a star - I will check the bra converter

I love the LK Bennett one as well