The humble mirror is nothing more than a greenish block of soda lime with a shiny back.
What are mirrors made of?
The mirror you have stuck to the front of that wardrobe is actually nothing more than a Soda-lime silica glass substrate with a silver backing. This soda-lime mixture is actually what gives it its true color, which is actually green, yes green.
Mirrors are not white
Simple, white reflects all colors in all different directions, in a process known as a Diffuse Reflection, whereas mirrors reflect colors straight back in the direction its facing as a concentrated source, which is known as a Specular Reflection.