Replacement fluid for living jewel

[Martin]

Hi All, I have recently picked up a living jewel where the liquid appears to have taken on a greenish hue. It runs really well and you don't really notice the discolouration when it is on, but when it is off, it looks 'mucky' next to my other ones. None of my other ones has done this so I don't know if the new one has been exposed to environmental conditions it didn't much like, or whether the fluid in this lamp was switched out for a home brew at some point... Either way, I just wondered if anybody knows of a place whereby I can buy replacement fluid (ideally ready mixed because chemistry and me is doomed to failure as my old school teacher will attest). I'm UK based since geography may affect what chemicals can be shipped where etc. Thanks All!