Have you tossed it yet? There may be a few simple chemical tests that would help explain the green coloration, particularly if you have a reasonable idea of what materials the juice will have been in contact with. While chromium seems like the most likely candidate based on the colour alone, it's a tad surprising that it would have got corroded by a relatively weak acid. Complexation is another possibility which can lead to enhanced dissolution of metals, so an over-oxidised metallic surface may be behind this phenomenon.
Besides copper being the other suggestion for candidate metal contamination - which I find implausible on account of copper complexes normally being far more in a bluish direction except in the case of its green chloride complex - there's also nickel which tends to form paler green shade (at least when divalent, as it would be here… but let's not get any more over-complicated).
The presence of a nitrogenous base may also lead to a dramatic shift in colour, such as in the case of its deep indigo ammonia complex, so there's a possibility that a small amount of metal contamination could be displaying a surprisingly intense colour.
While the decision not to use the juice is undoubtedly the correct one, it should be possible to recover the DMT by diluting the juice, adding base and pulling with naphtha as normal. This should leave the transition metal contamination behind, although you may have to let the transition metal hydroxide (if any…) settle out before doing any pulls, so this could be a bit fiddly if the DMT has decided to stick to the TM ions.
Sorry for making it sound so complicated
