As you seem so concerned with the "facts", a more accurate description would be a "hose bomb" as it's made with a garden hose or similar tubing. The effect is more of a firecracker than an actual bomb.

I seriously doubt that those were in the hackspace.

Sounds more like a serious case of having the hackspace in the wrong building with the wrong neighbours.

Well, I don't know who had them, but Sydsvenskan (Swedish newspaper) published the list of impounded goods, and there were 6 pipeboms on there.

No there where 6 "slangbomber" which is a home made firecracker, not a pipebomb.

Yeah, also listed in the police press release. Together with green lasers (not listed as missing from the hackspace), pepperspray and some other questionable stuff ...

Oh no! Not green lasers!

The full report makes clear that it wasn't the colour that was the problem as such, but the fact that they where stronger than what is allowed to own without permission.