There may be a lot of variations on this but mine is to cover freshly chopped comfrey (or any herb) with olive oil in a jar and leave in a sunny window for awhile or, sometimes, keep that same mixture warm (I've heard of using a crock pot) for a length of time but never boil as you mention above

The herb should still have it's nice green color in the end. Yours looks as though there might be too much beeswax to oil, maybe. For awhile I added the contents of a vit. E capsule to help preserve. If I make a lot I keep in the refrigerator, but mostly just in a dark cupboard and I try to only make enough for a year or so. Right now I have too much calendula oil but I am adding coconut oil to it and it is a wonderful winter salve for dry hands.
I think if you heated/boiled? it for any length of time that would have driven off any moisture from the fresh herb. The herbalists I know like to use fresh herbs for tinctures and salves whenever possible.
I strain off the herb before adding beeswax...maybe you could still do that and have a nice 'green salve'.
I do use calendula petals dried not fresh, for that oil...I grow it and dry the flowers and then pick off the petals......it is a beautiful color.