First time dyeing with natural dye

On Friday night, I decided that I was going to dye some merino top with dye made from onion skins. Now mind you, I've never dyed anything, let alone top, with natural, made from scratch dye. On Saturday, I peeled a pound of yellow onions to get 1 oz. of onion skins. (So that the onions didn't die a slow death in my frig, I made onion soup.) I steeped the onion skins in simmering water for about 40 minutes. I steeped the top in a mordant of cream of tartar and alum for about 45 minutes. I then left both to cool overnight. The next day I strained the onion skins and had a lovely dye stock that was a warm brown. I added what looked like enough waterto the dye potto cover the top. Plunked in the top and set it on the stove to simmer for about 40 minutes. The dye exhausted after simmering for 30 minutes. I let the whole thing cool to room temp, drained and carefully rinsed the top. I got this lovely yellow. I can't wait to spin this up!