Before the black goo was green goo

Black goo can hide and sneaky up on folks and BANG change you into a xeno... just sayin.

i dont get what you mean by that image? But yes i think the Goo that was given to the Sacrificial Engineer was different to what is in the Urns. The only proof to say its the same would be if we found out what would have happened to Holloway if he never got toasted. My theory is that we see the substance the Engineer uses break down his DNA into building blocks that went on to mutate and evolve into different kinds of organisms on Earth but all that have similar traits and DNA. The Black Goo in the Urns we saw effect the Worms and change them into snake like creatures with some Xeno traits, we see that a infected Holloways Sperm may had been what leads to Shaw giving Birth to a Organism that has similar traits to the Face Hugger and thus lead to Deacon that has similar traits and look to the Xeno. We then have Fifield, look at the concepts not used and there are another 3 types of Fifield and two of those looked very Xeno in contrast to the mutated swollen head dude. This makes me believe that the Engineers used a similar process that they used to break down the Sacrificial Engineers DNA into a substance that started the building blocks of life on Earth, they must have used similar on a Xeno to then break its DNA down aswell. But where as the Sacrificial Engineers DNA dissolved into the Water at the Water Fall, i think the Xeno broken down DNA was collected and stored within the Urns.

The Goo was green but they probably changed because it was seemed too environ-mentally friendly

that is actually orange. Or maybe purple. Dunno... pink?

Black goo is more sinister!