I just got back from Sydney, where I purchased my EZ tester. Curious I was so I tested pills the day I got it. I tested four different pills in one night, white hearts, green euros, green martians, and some other green euros. All of these turned brown to orange. Nothing else was available so I complained and got one of these speed bombs for cheap. And that is what they were.
The next night I got a hold of some green CU's. These turned black immediately. Very strong pills, I made the mistake of taking two at once. One would have been enough.
The EX test from Australia is accurate. Stick by it's results!