Color liquid crystal displays and display backlights

A display comprising:

• a display panel and a backlight,
• wherein the backlight comprises a blue light excitation source and
• a multi-layer wavelength converter film,
• wherein the multi-layer wavelength converter film comprises a wavelength selective filter film layer and a photoluminescence film layer,
• wherein the photoluminescence film layer comprises a light transmissive polymeric binder material incorporating a green photoluminescence material and a red photoluminescence material;
• and
• wherein the wavelength selective filter film layer is transmissive to blue light and is reflective to green and red light,
• wherein the multi-layer wavelength converter film is positioned between the blue light excitation source and the display panel, and wherein the multi-layer wavelength converter film is a unitary construction, wherein:
• the photoluminescence film layer is fabricated directly onto the wavelength selective filter film layer having no air gap between the layers;
• or
• the photoluminescence film layer is fabricated separately to the wavelength selective film layer and directly bonded to the wavelength selective film layer with a light transmissive material with no air gaps between the layers.