Qualm entered English in the 16th century, with meanings like doubt and uneasiness.. Usually a qualm comes from doubt about an action and a feeling that you are doing, or are about to do, something wrong. It isnt a bad feeling about another person's behavior but about your own.
Fluorescent lamps-These have the advantage of higher light efficiency with low heat. This type of lamp is the most widely used for supplemental light. It is available in a variety of colors but cool-white lamps are the most common.
Unlike halogen bulbs, LEDs offer a choice of light colour. With white light there is a choice between warm white, Natural White and pure white. These different light shades are assigned Kelvin ratings. A low kelvin rating is assigned to warmer shades of light, a higher rating denotes a cooler shade of light.