As a beginner, I am very happy with the result. I have dyed 2 merino knit garments with black. The tshirt was originally a dark colour and a cardigan which was a light oatmeal colour. I also dyed another garment using a brighter colour.
Before I was confident enough to try I did have to do a bit of extra research to work out how much dye and citric acid as the link to the instructions provided are in pound and ounces and generally a US tablespoon is smaller than an Australian.
The hot water stove top method with this dye produced a superior result to the Rit I tried previously.