Hope I can explain this. The snowballs alternate with nine patches. In the red and green quilt, Half the white snowballs have red corners, the other half have green corners. The nine patches are all the same, they are just rotated so that the proper color aligns with the snowball corner.
If these are 9" finished blocks, 9 1/2" unfinished --
9 1/2" white block with 3 1/2" red or green squares for corners.
The nine patch would be 3 1/2" squares -- GGR across the top -- RWR across the middle -- RGG across the bottom.
The first row would be 3 nine patches alternated with 2 snowballs with red corners. The nine patches would have the double red on top.
The next row would be 2 nine patches alternated with 3 snowballs with green corners. The nine patches would have the double green on top.
Repeat
)
Of course, I haven't tried this yet, but that is how I see it.
Good luck, Ann