> In one of the Knights maps, "Kingdoms" perhaps, the King could cast a spell that turned all corpses near him into living clonks on the player's side. Their clothes changed colour.

The Revaluation spell also can change clothes. I've not seen the raise-undead spell, but I'd guess that it also instantly changes the appearance of the Clonks, suggesting some form of teleportation.

> Perhaps Clonk clothing isn't actually clothing. It could be a part of their biology-being, capable of changing colour to match whoever they're loyal too.

That's not consistent with the official artwork. For example, the title screen I've taken my avatar from clearly suggests that the blue stuff is separate from the skin-colored stuff, as do the pictures of the CX Clonks.

Hm, the stretchy clothing theory is also contradicted by the loose fit of the sleeves in those pictures. So teleportation or some unseen technique seems the only remaining explanation. Given the prevalence of teleportation in Clonk (buying/selling stuff in the base!), I'd favor that explanation.