There are embossed Davis & Miller umbrella inks and I have seen some smaller embossed pontiled cylinders with partial labels for black ink. I think these are just a larger size. And the fact they come in color also makes sense as most pontiled master inks come in color
Its just some iridescence, the bottle is completely aqua. Unlike a lot of collectors I don't tumble my bottles... I like them the way they come out of the ground.