The Nook Glowlight 4e is available from Barnes ... the color temperature and adjust how warm or cool you'd like the light to be. For those looking to avoid blue light in the evening, this ...
With the Nook GlowLight 4 (and any other Nook I've used ... You can manually set the backlight to Night Mode using a slider to change the light from a cool blue light to a warmer hue.