Kardashians Face Another Khroma Challenge

As we previously reported ... Kim, Kourtney and Khloe are about to launch a new makeup line which they're calling Khroma (they love the "K" thing).

Problem is ... they've already received legal threats from a Bev Hills makeup company called Chroma over alleged name-stealing ... and now ANOTHER company has entered the mix.

The new company is called Kroma (no "H") ... and according to documents filed with the U.S. Patent and Trademark Office, it already locked down the legal rights to that name back in January.

So when Kroma (no H") found out about the Kardashian line ... sources say the honchos were angry ... and immediately fired off a cease and desist letter to stop Khroma (with "H").

We've obtained official docs which show the U.S. Patent and Trademark office had already REJECTED a trademark request by the Khroma people (with "H") back in September ... because the name was too similar too Kroma (no "H").