I agree, it looks more like plant matter - like your hibiscus leaves - and not mold or DOS. A DOS, btw, will often have the smell of rancid oil. I don't use FOs, but had a heavily scented bar from someone else that had DOS, and on close inspection I could smell the rancid oil. But, that might be because I have the nose of a dog and I know the smell of rancid oil.
Since I think you said you use the leaves from already steeped tea, I'm guessing it's not the hibiscus leaves bleeding color. I'm thinking maybe just take more time blending them, or maybe they did bleed and just need to be a bit more dry before you add them. I let my used tea leaves dry until they're at least just a little moist.
One thing I've found helpful when adding plant matter, like ground oatmeal or orange rind or tea leaves, is to pre-mix (and mix til ya can't mix no more) the plant matter in a set-aside amount of soaping oils. Doesn't take much. I use about 4 oz soaping oils for 1 oz ground oats. You also have to take your time with stirring them into the emulsion. I find in this that stirring works better for me than stick blending, but that may not be true for you. Even the smallest clumps will turn into holes or funny looking masses. I've also had success with pre-mixing with glycerin. Pre-mixing with water doesn't seem to help and seems to increase clumping. Swirling it into the batter just before or after pouring is usually just a big mess, especially with HP. And adding it to the lye water, even when you were told not to...well... Can you tell I like adding plant matter to my soaps? LOL
EDIT: Now that I'm re-reading your posts I'm not sure if the leaves you added had already been steeped. If not, then they might have just bled. This can be solved by using leaves that have already been steeped and dried a bit - used tea leaves - or sometimes by grinding them finer, to a softer powder. Some leaves, like black tea, bleed more than others and some, like green tea, can prove difficult to prevent coloring the whole batch. I find flower leaves are usually well behaved, but it's been a few moons since I used hibiscus. My notes just say that it irritated my skin leaving it red (newbies get tested on the inside of my elbow).