The two most popular types of glass are original clear and low iron.
3/8" Clear Glass
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3/8" Low Iron Glass
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As you can see, regular clear glass casts a greenish hue against white or light colored backgrounds.

Whereas the low iron glass shows off the true color of what's behind it.

here is the boring scientific description of glass

Low-iron glass is sold under various brand names.

Guardian Industries calls it "Ultrawhite", Pilkington calls it "Optiwhite", Vitro
 PPG Industries calls it "Starphire".[8] Other brand names include "Starlite", "Krystal Klear", "Diamant" and "Eurowhite".