I am really enjoying using KWZ inks (other than the vanilla scent), and I've been looking into finding my perfect olive green ink. One of my requirements is good water resistance -- it does not need to be 100%, but the writing has to withstand being touched with damp hands or a small spill and still remain easily legible. I hoped KWZ I.G. Green Gold was going to be it, but when my bottle arrived, I've found that it's really more like a somewhat olive-leaning dark green. Not a green-gold as one might imagine (or olive). In a moment of inspiration, I decided to see what will happen if I mix I.G. Green Gold with KWZ Honey. Honey is a translucent and "layerable" honey-caramel color that can shade to off black if piled on. I.G. Green Gold is a very saturated low transparency ink. Both have silver sheen outline, but I.G. Green Gold just barely a hint of it, whereas Honey sheens silver around the letters very easily on good paper.
Here are my results. No precipitate or odd behavior found so far. I very much like the first mixture and will be using it from now on in an empty Iroshizuku bottle.
KWZ "Olive #1" : KWZ I.G. Green Gold 3/4 : KWZ Honey 1/4
KWZ "Olive #2" : KWZ I.G. Green Gold 2/3 : KWZ Honey 1/3