number of studies which show that it's not as easy
as 'see some blue
light = your nocturnal period is disrupted' as would be the conclusion
from the popular press articles. This paper
. . . and a simple experiment, . . .
if you see a driver of a car who seems to be drowsy and a bit out of it,
shining a flashing blue light in their back window will wake him up and
raise his heartrate!
(that might not be entirely due to "blue receptors")