All the oil I'm getting is in red bottles, but there was a black one in the plane when I picked it up. I thought it was simply older packaging, but I note that there is a year-old revision (R8) to
SI-912-016. The older revisions I had seen listed a dozen or so different oils as being suitable. The newest lists
only Aeroshell Sport Plus 4. It further says to use the red bottles -- although it notes that the black bottles can be used until expiration. I've never noticed an expiration date on motor oil.
So maybe they changed the additive package a little, or maybe they just got a Rotax certification and changed the package. Don't know. But the black bottles are OK to use until their expiration date, according to Rotax.