Hydrogen Basics and Colors Explained

Hydrogen colors explained
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The following article aims on explaining the basic elements of hydrogen, as well as the spectrum of hydrogen colors.
In a fuel cell, hydrogen is a clean fuel that only creates water when burned. Several home energy sources, including natural gas, nuclear energy, biomass, and renewable energy sources like solar and wind, can manufacture hydrogen. Because of these characteristics, it is a desirable fuel choice for transportation and electricity-generating applications. There are numerous uses for it, including in homes, cars, and portable electricity.

The energy created from other sources can be transported, transported, and stored using hydrogen. Several processes can be used today to manufacture hydrogen fuel. Today, electrolysis and natural gas reforming, a thermal process, are the two most used techniques. Solar-powered and biological processes are some additional techniques.

Hydrogen Basics


Through a procedure known as electrolysis, water may extract hydrogen and oxygen. In an electrolyzer, which works somewhat like a fuel cell in reverse, electrolytic processes take place. Instead of harnessing the energy of a hydrogen molecule, as a fuel cell does, an electrolyzer produces hydrogen from water molecules.

Thermal Process

Steam reforming, a high-temperature process in which steam combines with a hydrocarbon fuel to make hydrogen, is commonly used in thermal processes for producing hydrogen. Hydrogen can be created by reforming a variety of hydrocarbon fuels, such as natural gas, diesel, renewable liquid fuels, gasified coal, and gasified biomass. Today, the steam reforming of natural gas produces nearly 95% of all hydrogen.

Solar-Driven Processes

Light serves as the catalyst for the creation of hydrogen in solar-powered processes. There are a few solar-powered processes, such as solar thermochemical, photoelectrochemical, and photobiological ones. Hydrogen is created by photobiological processes from the natural photosynthetic activity of bacteria and green algae. Specialized semiconductors are used in photoelectrochemical processes to divide water into hydrogen and oxygen. Water splitting reactions are frequently driven by concentrated solar energy along with other species like metal oxides in solar thermochemical hydrogen generation.

Biological Process

In biological processes, they use microbes like bacteria and microalgae which can also produce hydrogen. While photobiological processes use sunlight as the energy source, microbial biomass conversion uses bacteria to break down organic matter, such as biomass or wastewater, to produce hydrogen.

Hydrogen Colours

We outline the spectrum of hydrogen colors, from green to pink, as well as the various production methods. But hydrogen isn’t a colorless gas, is it?

The gas hydrogen is indeed invisible. Therefore, despite their colorful descriptions and a bit of confusion, there is no discernible distinction between the various forms of hydrogen.

Are you prepared to unravel the hydrogen’s present color code?

hydrogen colours spectrum
Green hydrogen

The hydrogen produced with no harmful greenhouse gas emissions is known as “green hydrogen.” Green hydrogen is produced by electrolyzing water with clean electricity generated in excess from renewable energy sources, such as solar or wind energy. Hydrogen and oxygen are separated from water in electrolyzers using an electrochemical reaction; no carbon dioxide is released during the process.

Because generation is costly, green hydrogen currently makes up a small portion of all hydrogen. Green hydrogen will become less expensive as it gets more prevalent, just as the cost of wind energy has decreased

Blue Hydrogen

Using a technique called steam reforming, which combines natural gas and heated water to create steam, blue hydrogen is mostly made from natural gas. Hydrogen is produced, with carbon dioxide as a byproduct. So, in order to capture and store this carbon, carbon capture and storage (CCS) is crucial.

Due to the fact that the steam reforming process doesn’t actually prevent the production of greenhouse gasses, blue hydrogen is occasionally referred to as “low-carbon hydrogen.”

Grey hydrogen

At the moment, this method of producing hydrogen is the most popular. Natural gas can produce grey hydrogen, using steam methane reformation, or methane, without releasing any greenhouse gases into the atmosphere.

Black and Brown Hydrogen

These black and brown hydrogen are the complete opposite of green hydrogen in the hydrogen spectrum. They are the most harmful to the environment since they are produced using black coal or lignite (brown coal).

For further confusion, the terms “black hydrogen” and “brown hydrogen” are frequently used interchangeably to refer to any hydrogen produced by the “gasification” process from fossil fuels.

Recently, new brown coal-to-hydrogen project was unveiled by Japan and Australia. In Australia, brown coal will be used in this project to create liquefied hydrogen, which will subsequently be transported to Japan for use in low-emission applications.

Pink Hydrogen

Nuclear energy is used for the electrolysis that produces pink hydrogen. Purple hydrogen or crimson hydrogen is the further name for nuclear-produced hydrogen.

Additionally, the extremely high temperatures produced by nuclear reactors might be utilized to produce steam for more effective electrolysis or steam methane reforming that relies on fossil gas.

Turquoise Hydrogen

This is a brand-new addition to the hydrogen color wheel, and scaled production has not yet been shown. Methane pyrolysis, a procedure that yields solid carbon and hydrogen, is how turquoise hydrogen is created. If the heating process is fuelled by renewable energy and the carbon is either permanently stored or consumed, turquoise hydrogen may one day be recognized as low-emission hydrogen.

Yellow Hydrogen

The term “yellow hydrogen,” which is relatively new, refers to hydrogen produced by electrolysis utilizing solar energy.

White Hydrogen

While hydrogen is a type of naturally occurring geological hydrogen produced by fracking and found in subsurface deposits. At the moment, there are no methods to utilize this hydrogen.

Hydrogen colors details

Sustainable transportation development

Sustainable transportation development and commercialization have advanced quickly in the previous several years in an effort to lessen climate change and the harmful effects of emissions from conventional fuel cars. Since there is significant potential for building convergence between climate change mitigation efforts and sustainable development goals in the transportation sector, the goal is to raise awareness of sustainable mobility and implement sustainable development. Hydrogen energy-based technology is viewed as having the potential for future transportation. Due to the rise in environmental concerns, such as greenhouse gas emissions and environmental sustainability. The only fuel in the forthcoming meeting of the requirements for sustainable mobility and the development of hydrogen-powered cars, according to technical elements presenting hydrogen generating and storage technologies, is hydrogen.
To enhance the use of hydrogen as a transportation fuel in the future, many governments must coordinate their energy needs. The first steps toward a hydrogen economy, which ensures energy security, would surely be paved by policy and regulatory measures as well as greater global investment for research and commercialization activities. If we follow the right actions and procedures to make hydrogen safe, dependable, and robust, it has a lot of potential in the transportation sector.


The development of hydrogen is anticipated to go more quickly than many might anticipate and to play a significant role in the future of energy. Business executives are becoming more aware of the necessity to comprehend hydrogen in order to identify future prospects. However, it is challenging to stay on top of the major trends and advances with all the buzz around hydrogen. It is pretty much clear that, we should definitely move away from fossil fuels and hydrogen may be a key element in the future in this direction.

Written by our Energy Enthusiast
Pavlos Hitiris

Pavlos Hitiris Author

Pavlos has a Bachelor in International and European Studies from the Panteion University of Athens. He has worked successfully at a Law Firm in Kolonaki, Athens. Currently, he is working at a Solution Provider/System Integrator Company in Athens. Postgraduate student of the MSc in Energy: Strategy, Law, and Economics at the University of Piraeus in the faculty of International and European Studies. He speaks Greek, English, and German. Keen on Middle East culture and history.

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