That's because Kepler-186f orbits a red star, and we're just speculating that perhaps the plants there, if there is vegetation that does photosynthesis, it has different pigments and looks red.
Itu karena Kepler-186f mengitari suatu bintang merah, dan kami hanya menduga mungkin tumbuhan di sana, seandainya ada vegetasi yang melakukan fotosintesis, mereka memiliki pigmen berbeda dan terlihat merah.