RKreutzer has got it right.
The yellow 'shading' between the 50 and 60 km/h marks is there to indicate the speed range you should be driving in, when in city areas. Many european cars have 'shading' in the 110 - 120 km/h marks to indicate the speed range for the freeways too. It's as simple as that..
Never criticize someone until you've walked a mile in his shoes. That way, when you do, you're a mile away -and you have his shoes!
'86 300E optically converted to '95 E300 (Sold)
-Blauschwarz on silver
-17" AMG & 15" AMG for winter