Ive had these "red rockstars" on a few occasions in Ibiza, there are definitely a few batches of them, I tested about 3 different ones of them they all went black on my marquis so thats all I can say. Although the first time I took them they were quite a light pinkish colour, more than red, they contained MDMA but they were not very strong and not much empathy at all. The second + third time I took them they were quite a darker red but I thought they were alot stronger and a little more empathy.
Anyway the 4th time I did pills in the week was the purple diamonds, and these blew the rockstars out of the water in terms of good quality mdma, not just strength. Considering it being the 4th time in a week aswell i was quite impressed. The "copyright" brand has always been a bit dodgy really, they were producing mephedrone pills at one point also there was alot of fakes going around last year..