1971 Mercedes-Benz 220 D

The effectiveness of car lights is not only determined by the power of the light, but also by how and where the light is shone. Too much reflection of the lights and the pupils in the eye become smaller and less is seen. Normal headlights have to shine most light far away and less directly in front of the car.
There has also been a discussion about yellow lights. Yellow lights are considered less blinding, so safer for all. France made them obligatory, but now science has moved on, and yellow lights are outlawed in France.
This car has normal headlights for dipped and high beam, below that there are fog lights. The two yellow ones might be extra fog lights (as the lens suggests) or extra high beams. Yellow fog lights are considered by some to be superior to white fog lights, but scientific proof for that is scarce. And then: in dense fog nothing really helps to see more, not even yellow fog lights.

The 220 D was the most popular model of the W114/115 model range. For years it was the most powerful diesel engine of Mercedes, until the 240D took over.