Everyone must dress in white – best if they don’t spend too much on the clothes because as you arrive you are given a colour marker pen ( make sure it is washable otherwise your furniture could take some punishment). This is a great ice-breaker and as the night rolls on and the drinks soak in the clothing evolves – who knows you might take home something collectable.
You could extend the theme to allow for some freestyle graffiti on screens made of old panel board (check out demolition recycling in your area ). Once again you can make this a team or individual competition then raffle off the end results for charity.