Reimport car and fine dust badge

Hello. I have the following question. I have a VW Diesel (built in 2000) which has a red fine dust badge. Now I have a DPF retrofitter and only the yellow badge, because the car is probably a reimport. But it meets the same standard (also in terms of fine dust) as other VW Diesel (e.g. Golf 4) too. Do you have to cope with such an “unjustice” or can you possibly do something like a special AU test or something like that? Because pure of the values it would be the Green Pla like other similar cars also get chain.