Very nice.
You might consider at least basting some of the green and white hexies as you go along. That way you don't get to the end and get bored with only those colors to work with! You don't have to attach them just baste and wait till you are ready to construct the whole thing.
Just a little experience talking.
It is a great beat-the-heat project when it is in the early stages.
Keep up the good work.