... glass: 1.material:colored optical glass 2.color:red,yellow,orange,violet,blue,green etc 3.size:customization (1).material:colored ... optical glass .(2).color:red,blue,violet,green,yellow etc (3).according to the requirement dimensions. Color optical ... red glass, ultraviolet black glass, neutral gray glass, orange glass, green glass, yellow glass, band-pass filter, and filter specially used ...