A quantitative color temperature scale has been developed and implemented on the updated “Painter’s Guide” app. This app is free for everybody to use. Just go to my website and click the “Apps” tab, then select “painter’s guide”. I know the color temperature is a relative concept. However, I think it will be helpful if we have an absolute quantitative scale, so we can manage the subtle temperature change more precisely. If you are you interested in the scientific base of this development, please contact me.