Beautiful quilts .... both of them.
I've also mixed denims and didn't worry about it because they were utilitarian quilts for the dog's bed and to be kept in the car. They have all worn very well .... and the one for the dog has been washed repeatedly. I don't use batting in any of these quilts because the denim is a heavy fabric. I'm making one now mixing denim and chinos and other durable fabrics.