In fact, Kepler-186f receives only 32 percent of the stellar flux (i.e. sunlight) that we receive on Earth. As a comparison, Mars receives 43 percent of the stellar flux that Earth receives. This means Kepler-186f will be dimmer than Mars. As we all know, Mars is a freezing place with little atmosphere, but if Kepler-186f has a thicker atmosphere than Earth, then perhaps it can incubate liquid water on its surface.
ANALYSIS: Earth-Likenesses: Have We Discovered Earth 2.0?
This "Earth-like"* world is 10 percent larger than Earth, so depending on its mass Kepler-186f could indeed support an atmosphere that is many times the density of Mars' (and indeed Earth's) modern day atmosphere.
With this in mind, the sunsets on Kepler-186f could be breathtaking. As the planet orbits its star in a very compact orbit (completing one "year" in 130 Earth days) and the M-dwarf generates less energy than our sun, the planet's star Kepler-186 will appear bigger in the evening sky. Starlight will already be shifted toward the red end of the visual light spectrum and, depending on atmospheric composition, would produce a blood-red sunset.