Nicole Richie and Joel Madden booked a sitter and went to dinner last night with Cameron Diaz and Benji Madden -- and Jessica Alba and her hubby Cash Warren. Make that a triple date!

Joel was sweet enough to get the car door for his lady love, who's dyed her hair even pinker since we saw her last. We're not saying this looks good, but it definitely looks better now than it did last week when she appeared on The Ellen DeGeneres Show.

Benji also opened the door for his wifey, and we definitely caught her giggling in the car after dinner. Ahh, the bliss of being a newlywed!