Boy, I HATE telling this story about my matching shirts, but here goes.....
The first time we went to WDW, I made all of us yellow shirts, so that I could easily spot everyone in a crowd---simple really, used yellow Hanes shirts and the dark iron transfers from Avery, Disney Pic with The Aaron Family Vacation and the year. I had a 4yo, 7yo, 11yo and x-H, myself and my mom.
I was in Mickeys Toontown in MK and my 4yo wanted to play in the play area there. I sat down on a bench and had dropped my camera in an earlier attraction so I looked down to fix it, no more than probably 1 minute and my son was gone!!!
I started to panic!!!
I searched there and went out of one of the exits, and see my son, a castmember and a young couple coming at me. I was so greatful!
The man in the couple had seen our shirts and had laughed that he might have to divorce his new bride if she ever made him wear those, earlier in the day! BUT he knew exactly were I was at, when they saw my son and no other Yellow Shirts with him!!!
As soon as we(my son and I) were back together, he turned to his bride and said Ok, every trip with kids we will have them and WEAR them!
I offered to buy them dinner, anything, I was so greatful to them, but the castmember turned to me and said very calmly Don't worry Disney Always takes good care of good samaritians!
I was so greatful and the shirts really saved us alot of panic!
A funny one on this, on this same trip, my mom loves the blue fairy godmother from Sleeping Beauty and I was walkieing her and she wasn't answering and some man got on and said does she have on a Blue Fairy Grandmother shirt and I said yeah, I was at the GMR in DHS, he said don't worry she is walking towards you! We had been on the same frequency most of the day and we kept helping him out and him us out throughout the day! We met them on our way back to the hotel that night, we laughed the whole way back, he told my mom he wouldn't be there to save her tomorrow, so she better keep her walkie on!!!
I hope this helps you convince your husband, sorry about the MEGA long post!