Which one of the following is the colour of hydrogen gas?

Which one of the following is the colour of hydrogen gas?

Light yellow
Orange
Black
Colourless
This question was previously asked in
UPSC NDA-1 – 2022
The correct answer is Colourless. Hydrogen gas (H₂) is a colourless gas.
– Hydrogen is the lightest and most abundant element in the universe.
– At standard temperature and pressure, hydrogen exists as a diatomic molecule (H₂) and is a gas.
– Pure hydrogen gas is colourless, odourless, and tasteless.
– It is also highly flammable.
Many common gases like nitrogen (N₂), oxygen (O₂), noble gases (He, Ne, Ar, etc.), and carbon dioxide (CO₂) are also colourless. Some gases do have colour, such as chlorine (greenish-yellow), bromine vapour (reddish-brown), iodine vapour (violet), and nitrogen dioxide (reddish-brown).