The color blue was chosen after much testing, based on the generally accepted perception that blue is calming. Blue light in high doses can help wake you up by inhibiting melatonin secretion, but Dodow does not. Being projected on the ceiling, the light signal, at its maximum intensity and for someone who is lying in bed, has a very low intensity (less than 1 lux), compared with the relatively strong intensity of a computer or television screen (about 60 lux at a distance of 50cm). In addition, the exposure time (between 8 and 20 minutes) is low. Dodow's impact on the circadian rhythm is therefore almost zero or, in any case, far too low to delay falling asleep and counteract the positive effects described above. The luminous halo is, therefore, in fact, more similar to color than to light.