Is it just me?
 

Why does it look like the front quarter panels on many of the 123's I see seem to be a slighty different in color, or shade of color than the front doors?

Probably been in a fender bender and the paint had faded. depends of the quality of paint that was used.

Charlie ☺

After 30 years or so, the odds of a partial repaint are pretty good.

Jim

Different colors
 

I have seen this on many cars including one that I purchased a few years ago. I dont know why but I've seen it too. Is it possible that the front tires kick up alot of road grime that make the paint fade or at least take the wax off and oxidize the paint? Take some rubbing compund and wax to it and see if you can get the paint to match.
-Stephen

I've got one of those also. Left side only - and ever so slight. Can't even notice most of the time. Always figured it was repainted.