english: 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.
non_english: Kepler-186f obieha okolo červenej hviezdy a ak by na planéte bola vegetácia  a prebiehala tam fotosyntéza, možno by tráva mala  inú pigmentáciu a bola by červená.