I am planning on making several batches of soap with a hanger swirl in the BB 2 lb silicone loaf mold. I would them all to look the same and be colored with light pink and grey swirls. I have electric bubblegum and black luster mica from BB. Any idea on how much I would need to use per mold for each color? I don't have grey mica so I'm hoping if I use a smaller amount of the black it will suffice.