Starting in the upper left - top row is dark over medium; dark over medium; and medium over light.
Next row dark over medium; medium over light; medium over light.
Bottom row all medium over light.
It is hard to tell, I had the directions on a piece of paper but can't find it now. Also DH tends to play fast and loose with colors, when he runs out of mediums he substitutes darks and vice versa. He made this one. I hate to tell you how small the triangles are, but the pattern would work with any size.
When you set the blocks together, put 4 upper left corners together to make a larger block which will have light on the four corners. Then when you are setting the larger blocks together put 4 light corners together. And so on.
Hope this makes sense, this must be the worst tute ever.