what to wear to early evening drinks and canapes party?

[racingheart]

It's a big works do. Some colleagues who are now old friends will be there, and I'll probably just catch up with them all night, so not too formal.
Knee high dress and heels? Or black trousers and a pretty top? I never get this sort of thing right and am often over dressed.
What about hair and accessories?
First party in ages (sad!) so I want to make a bit of an effort.

Knee length dress and heels, both dark colours. I'd go for dark but slightly sheer tights. Simple, quality jewellery like a modern silver pendant or a modest solitaire stone.
Make sure the heels are comfortable enough!

Hair - I'd straighten my curly hair, what's yours like?

Thanks Milkybar. I have a nice dark dress that would work. But heels are all v high - more for parties. Got one pair of kitten heels that may have to do.

Hair's already straight but will blow dry it to give it shape.