I didn’t spot coverage of this story on more major news sites. This Indian source seemed less editorialized than others:
Environmental activists break into Sylt Airport in Germany and spray an orange color on a Cessna Citation corporate plane.
It appears that the aircraft operator will incur higher costs. On one of the Twitter accounts, a video of some of the activists painting an airplane with orange paint is shared. The engine is fortunate to be covered while they are painting it.
I don’t know what kind of paint they used, but environmentally-friendly kinds do exist.
Even if it wasn’t, I doubt that it could have done anywhere near as much damage as if the jet were to continue flying as normal.