Some time ago I made a purple monochromatic purple quilt for a friend of my daughter. It turned out very nice. I used a free pattern from JoAnn's that consisted of 4 12X16" blocks in the center, then decreased in size going across and up and down the quilt. It was a very simple pattern for a queen size quilt and depending on the detail the fabrics is a good way to show off your quilting if you like. Unfortunately I do not have the picture on this computer, so can't show you.
I say go for it. They look nice.