Check out the new fact sheet published by the DOE. It helps to clarify and dispel some of the myths surrounding LED lighting and its impacts on health.
I think this paragraph is the perfect summary:
What may be beneficial for an occupant during the day may be harmful at night, and may vary significantly between individuals in a given space. Complicating things even more is the need to balance the desire for alertness with preservation of normal circadian rhythms among night-shift workers, for example. Therefore, even if a prescription for effective nonvisual stimulation is developed, implementing the solution may not be straightforward, especially if there are users with different histories and needs occupying the space at the same time.
Translation: You actually have to consider the application very, very carefully before engaging these advanced spectral manipulation strategies. What is “right” depends on the specific application…even the specific time of day. Their is no magic “healthy light”…even daylight can be bad for your health — at night!