(TMZ) The Kardashian sisters aren't backing down in their war with a high-end makeup company -- sources close to the K-Krew tell TMZ, they've got a secret weapon to guarantee they'll prevail in court ... trademarks.The Kardashian girls filed requests to trademark the phrases "Kardashian Khroma" and "Khroma Beauty by Kourtney, Kim, and Khloe" earlier this summer.
The requests are still pending -- but sources connected with the family tell us, they're confident they'll be approved ... because the man behind the competing makeup line (named Chroma) hasn't filed for ANY trademarks.
As we reported, the co-owner of Chroma Makeup in Beverly Hills -- a guy named Michael Rey -- is threatening to sue the Kardashians over the Khroma make-up line, claiming the Kardashian line will cheapen the high-end company he's built over the last 12 years.
It's worth noting ... you don't NEED to register a trademark to pursue trademark litigation -- so Rey may NOT be up the creek without a paddle.
And there's this -- while we were looking up the Kardashian trademarks, we came across another makeup company named "Kroma."
"Kroma" filed for its trademark in 2010 ... so that could be another obstacle for the Kardashians. more on this story