Hello, my 280ce has blue and red markings on the steering rods... which is left , and which is right, please.........

Good question. to answer that people would probably need the year of the car. Typically the information that is needed is year, make (in this case they are all Mercedes so this is not needed), model (you have that), and engine if there are more than one option for that model.

But with that information I would shop online (I like rock auto but any of the better sites will post color pictures). Then in the description it will say fits 20XX or 19XX make model (left or right) tie rod. Then it is just a matter of matching your car and either the left or right one to a color. All assuming those are factory color codes. If not look for other differences between the two you have. and match the picture with the picture on the site.