My grandmother used to make quilts that looked like this....and she always tied them in red. Nice memory.
My father used to sell custom made suits, and some of her quilts were made from fabric samples Dad would have left over when new fabrics came out. Those were really heavy quilts, as I think she also used army blankets as batting. The goal was to keep warm, like someone has already said.
Of course, I wouldn't use suit fabric nowadays. Flannel might be a nice choice though. If you make it as close as you can to that picture, he will be very pleased....and slightly larger squares would be just as pleasing to him, and quicker to make.
I hope you end up enjoying the project. It looks like fun.
Dina