I've been using the red ink out of this collection, and one tip that I can pass on is that in order to get the gold to show up you should store your pen with the nib pointing down. The gold flecks tend to settle at the bottom of the converter, and bottle. Or you could store it up and end up with an almost pure gold ink by the end of the bottle!
iLeicaMikeThank you for this!! Haha Ive been trying to get the gold flakes to show up with no luck, such a simple solution i didnt even think of it -___-