I am a paint card liberator also
Most of the time people bring a swatch with them though. Most brides are pretty picky about colors matching and have the forethought to bring a sample of "their" colors.
The order forms and contracts that I use pretty much cover my butt for ANYTHING and I always get a contact persons name from the bride to verify the order upon delivery.
There are copies of my contracts in my photos if any of the newbies are looking for one.