Red Cabbage Dye

Results of dyeing with red cabbage leaves:
#1 (top) Small piece of test wool put in as leaves were simmering to extract dye. Color is a dusty blue pH is about 6
#2 Removed the leaves, added larger amount of wool, and this dyed a kind of
nondescript lavender. Don't know why it's different.
#3 Divided the dyebath and the wool from #2 into 3 parts. To one part I added washing soda (sodium carbonate) to raise the alkalinity to pH 9. Color changed to a nice green. (ammonia works also)
#4 To the second part I added powdered iron, which changed #2 to a grayish
green/blue
To the third part I added vinegar, increasing the acidity to pH 3. It didn't really change the color from #2, so I didn't include it in the photo.