[MJE60]

I assume your question relates to tail lights (rear) only. My understanding is that for legal reasons the actual whole tail light (rear indicator/signal) assemblies are different. They certainly have different part numbers. In the EU, rear lights must be red except for indicator/signal lights which MUST be amber in colour. In the USA, rear signal/indicator lights are USUALLY red but can be amber. I therefore do not believe this is a coding issue but the actual physical properties of the clusters. In any event, I doubt a green led through a red lens would give you amber, more likely imo it would give a brown or dirty grey colour. I assume you are aware that US spec red signal/indicator lights are illegal in the EU. I attach pictures of difference between parts, top is EU spec and bottom is US spec part. Imho, you will have to buy whole replacement rear light clusters/assemblies, luckily there are many used ones for sale on online market places. Good luck getting sorted.