Blue vs Green vs Pink Hydrogen: What the Colors Mean

Hydrogen classification by color has gone from industry shorthand to standard vocabulary. Understanding what each color actually signifies — production pathway, carbon footprint, cost — matters for project underwriting and policy compliance.

Grey, black, and brown hydrogen

Grey hydrogen is produced by steam methane reforming (SMR) of natural gas without carbon capture. It's the dominant production method globally (roughly 95% of current production), cheap ($1–2/kg), and carbon-intensive (9–12 kg CO2/kg H2).

Black/brown hydrogen is produced from coal or lignite gasification. Common in some regions (China), and very carbon-intensive (up to 20 kg CO2/kg H2).

Blue hydrogen

Blue hydrogen is grey or black hydrogen with carbon capture and sequestration (CCS) bolted on. Economics depend on CCS capture rate (typically 85–95%), transportation to sequestration sites, and underground storage costs.

Blue hydrogen levelized cost is $2–3/kg in good conditions, higher where CCS infrastructure is lacking. Lifecycle carbon intensity varies widely — roughly 1–3 kg CO2/kg H2 for high-capture-rate facilities. Importantly, fugitive methane emissions during natural gas extraction can significantly increase the upstream footprint; well-to-gate lifecycle analyses are essential.

Green hydrogen

Green hydrogen is produced by electrolysis powered by renewable electricity. Current cost range $3–6/kg depending on electricity cost, electrolyzer capex, and capacity factor. Lifecycle carbon intensity under 1 kg CO2/kg H2 when produced with low-carbon electricity.

Qualifies for full 45V IRA credit if temporal matching, deliverability, and incrementality requirements are met.

Pink hydrogen

Pink (or purple) hydrogen is electrolysis powered by nuclear electricity. Structurally similar economics to green hydrogen but often better capacity factor because nuclear is baseload.

Pink hydrogen has been politically contentious in Europe but recognized favorably in the US IRA. Several US nuclear plants have announced hydrogen production pilots (Xcel at Prairie Island, Entergy at River Bend).

Turquoise and white

Turquoise hydrogen is produced by methane pyrolysis — breaking methane into hydrogen and solid carbon without CO2 emissions. The solid carbon is a useful byproduct. Still in early commercial development.

White hydrogen is naturally occurring geologic hydrogen. A small but growing area of exploration. Probably not significant at utility scale in the near term, but promising deposits have been found in Mali, France, and the US.

What matters for projects

For regulatory compliance, lifecycle carbon intensity matters more than color designation. The EU's Renewable Energy Directive 3 (RED3) and the US 45V credit both define hydrogen quality by measured carbon intensity rather than by color label. This is appropriate — the color labels can be gamed; lifecycle math can't.

The Axis view

Color labels are useful shorthand for buyers and policy-makers. For project developers, the relevant questions are lifecycle carbon intensity, tax-credit qualification, and offtaker requirements. Getting those three right is what makes a hydrogen project work.