I too have plans to make a quilt for our GS. But I am doing an I SPY quilt. This would be an easy pattern for you to use also. Just cut squares, (you choose the size)and strip sew them together. You could add a print then a blue then a print then an orange then a print .....you get the idea. That way the prints wont all run together but will have a break in between them and still give him hours of enjoyment looking (I SPYING) the things on the qult.
Have fun let us know what you decide to do.