Hi Mueschel, Marked Gas Oil is the appropriate name for Green dyed Diesel which is available across various fuel stations in Ireland, including in Clarke's. I am not sure why this tag is not used as Marked Gas Oil is readily available across a lot of fuel stations in Ireland.
Here is are links about Marked Gas Oil:

https://www.revenue.ie/en/companies-and-charities/excise-and-licences/mineral-oil-tax/heavy-oil-used-for-private-pleasure-navigation/marked-gas-oil.aspx

https://www.revenue.ie/en/companies-and-charities/excise-and-licences/mineral-oil-tax/mineral-oil-traders/fuel-marker.aspx