I like the Contour range a lot, this line is historically not really known for being bright, usually they are regarded as a bit more on the warm-neutral side. The soft dome tweeter is not really harsh or exaggerated in the higher frequencies, but there is a slight recession in the upper midrange which could make the treble seem a bit more pronounced.
Measurements are available at Stereophile:
https://www.stereophile.com/content/dynaudio-contour-20-loudspeaker-measurements
I'm curious about the room setup and pairing in the store, it could be that something was causing them to sound brighter than they normally would.