Actually Grandpa looks more impressed in this photo ... or maybe he was trying to hide until the blanket?
The pattern was rotationally symmetrical in terms of which pattern block went where, and the colours ran from purple in one corner to green diagonally opposite with pink and cream as accompaniments. I could have been braver with the colour placing, but, you live and learn. Here's a photo of the blanket (without its border, I couldn't photograph it with the border as there simply wasn't enough floor space once Christmas hit), and a little closeup:
The squares are all from the "200 Crochet Blocks" book - granny square, corner granny, shell lace and willow.