They appear to be a US based company and advertise on www.behindthechair.com so I imagine it’s bonafide, although sounds a bit gimmicky. I imagine clients might not like the look of a grey paste on their hair when they’re getting highlights.
Matrix Light Master Lift and Tone is a bleach with built in toner and available in the U.K. if you were looking for an ‘all in one’ product.
It would be interesting to try the new product but I don’t think it’s sold over here yet? I’d be wary of buying hair colour products outside the U.K./EU for use on clients though, because you may not be covered by insurance if there’s any issues.