cold legs....tights for an afternoon party? and what colour?

[purplerain44]

hi there, I have an anniversary party to go to later this afternoon - at a house, probably spill into the garden. I've got this dress from H&M...

www2.hm.com/en_gb/productpage.0773463001.html

but do I go bare-legged and get cold legs, or if tights, what colour?

thanks!