I have and use one brown LG Rik. Works just as good as any of the others I have. VTC5, VTC4, MXJO... they all have about the same run time and performance in the old school vaping realm.
You're fine .. it is just the company protecting itself from frivolous lawsuits. I'm sure they sell way more of these batteries in laptops and other electronics without a problem.
I don't lose any sleep over it.. wouldn't be surprised if all of them start printing that on there batteries.