Red dwarves everywhere.

[far-trader]

Of course dim light is going to mean more than just how well you can see your surroundings unaided. Two things leap to mind:

1) Light deprivation depression, aka SAD (seasonal affected disorder) common in areas that experience long winters, the reduced daylight hours cause various levels of depression in people from none (or coping well enough) to mild (blues) through severe (full depression). Artificial full spectrum light exposure is the treatment.

3) Vitamin D deficiency, which can be treated with supplements or again artificial full spectrum light exposure.

...expect large indoor open spaces set up as park and beach scenes with a huge artificial sun to make it like summer on Earth, and work spaces overlooking same to take advantage of the light boost through windows and during breaks and foot commute.

 

[spirochete]

...expect large indoor open spaces set up as park and beach scenes with a huge artificial sun to make it like summer on Earth

Keep in mind that the quality of M-dwarf light changes during a flare, both in spectrum and brightness. Flare light is bluish-white like an electric arc; some astronomers have likened it to "an A-star on an M-star". Smaller red dwarfs will produce several flare events per hour; one or two of these, at peak intensity, create outdoor lighting on the planet (both hue and brilliance) like mid-afternoon here on Earth. The flare light typically reaches peak brilliance in less than 30 seconds and fades away over several minutes.

and work spaces overlooking same to take advantage of the light boost through windows and during breaks and foot commute.

Once the surreal novelty of perpetual morning wears off, the golden rays of an M-dwarf would probably get tiresome. Blue window tint can be used to restore a more visually pleasing color balance. This tint is like the CTB filters used by cinematographers, or the 80A filters used for white-balancing a scene in incandescent light.

For a 'minimal' red dwarf, complete color correction to 'normal daylight' or 5,550 K will reduce the available light by about 3 f-stops, or 12.5% of ambient light intensity - somewhat like looking though dark tinted windows at sunset.

3) Vitamin D deficiency, which can be treated with supplements or again artificial full spectrum light exposure.

Flare radiation is heavily laden with ultraviolet wavelengths. A breathable atmosphere will block most of it with a flare-induced ozone shield, just as our own atmosphere filters most of the sun's UV rays. At the peak of a flare, the unfiltered UV rays range from a few percent to double that of mid-day on Earth. Humans (caucasians, at least) should receive enough flare UV exposure satisfy most, if not all of their vitamin D requirement.