Opalescence
A milky, bluish glow in a translucent material that looks warmer when light shines through it.
Also: milky sheen
Opalescent materials look faintly blue by reflected light and yellowish or orange when lit from behind. Thin milk, some glass and common opal do this. Tiny particles in the material scatter blue light sideways and let the warmer colours pass straight through, much as the sky is blue and the setting sun orange. The term comes from opal. Precious opal goes further and shows flashing patches of pure colour, an effect of regularly stacked microscopic spheres, which is better described as a play of colour.