Of the three motifs that are used in making Tracy St. John’s groovyghan, I “saved” the granny squares for last because of all the decisions involved in making them.
Theoretically, there are 5040 possibly permutations using the seven colors I am working with. To reduce the number of decisions I would have to make I began working on all seven squares at once, and set down two rules of color choice.
The first rule is that no color can be used twice in a given round.
What this meant on a practical level was that I needed to begin by making 7 one-round granny squares, one from each of the colors I was using. Here are the resulting squares:

With the second round came a second rule: the color could not have already been used in a previous round in the square. Here is how the 7-round granny squares to-be looked after the second round:

Once I had the second round of each square completed, I moved to the third round, applying both rule one and rule two:

The first three rounds of all seven squares completed, I moved onto the 4th round and again applied both rules that I had used for rounds two and three:

I am now three rounds (times seven) away from completing the granny squares, and with an errand-free day ahead of me and my Clover chibi beside me, I think I just might get it done by sundown tomorrow.
I like how your groovyghan pieces are coming out – good work. 🙂
Thanks for showing me an easy way to use “random” colors for the seven granny squares. I looked at several sites that confused me more than helped me and your method was simple to understand and more importantly it works!