Chasing rainbows

For a colourless gas, hydrogen has lots of colours...

From grey to green and blue to brown, colour codes have been used to distinguish between different types of hydrogen.  These are often referred to as the ‘rainbow’ of hydrogen production pathways.

These colour codes have played a useful role in helping people understand the value of investing in hydrogen and its role in the energy transition and decarbonising hard-to-abate industries. But they have limitations.