Frank is wearing a blue/blue shirt/tie combination at work the day he takes Valerie home but is wearing a black plaid/red combination at dinner that first evening. Next day, at the 9 am briefing, he's wearing that same black plaid/red combo. At dinner that second night, he's changed to a red-blue plaid/blue combination. If these aren't goofs, then it appears that Frank dresses for the next day before dinner the previous night.