They're definately alien. Just... not something becoming to the pfhor. Circus clown aliens, maybe. The weirdest thing about it is replaying Pfhor Your Eyes Only where it got retextured with the new set. In my headcanon it's part of Durandal's "improvements" over their technology, but that refueling ship Thoth sends you to has the same textures, and returning to the Hang Brain area in infinity has it recoated in the Infinity Textures! My willing suspension of disbelief stretches that into "alternate timeline design choices" to explain it, but it takes a lot of willing suspension to reconcile the changing textures in each scenario.
Short summary of opinions: M2 pfhor textures make me puke. MInfinity is more dark, but not so alien like you said (sometimes I think it's a little too dark). M1 got it perfect, IMO. Dark, weird and alien, with some magentas and greens to make it not completely bleak (it's more restrained than the neon multicolors of M2).