Generally speaking, we're looking at any hydrogen that can be developed cleanly. While you will sometimes hear about various colour schemes, with blue representing hydrogen derived primarily from natural gas using carbon capture and storage, or whether you're using hydrolysis for what is sometimes called green hydrogen, we're really trying to move beyond colour-coding and focus on the carbon intensity of the fuel.
What we want are hydrogen and other cleaner fuels that are significantly cleaner than their current alternatives, so when we talk about the hydrogen strategy and about the work we're doing in R and D, we're talking about all forms of cleaner hydrogen.