It has been explained to Pearljam at least 3 or 4 times already why Neumanns sound darker than Genelecs, at least in farfield conditions. I don't know why he refuses to accept this explaination and still pretends to know nothing.This is very strange. My KH 120s are anything but "dark", "dull", "veiled"... In fact, their treble sound almost too much for me. I did not compare them to any of the Genelecs, but their crispness in the treble immediately stood out for me compared to my HEDD Type 07 MK2s, which are definitely not dark and have very detailed highs. It took some time for me to get used to the Neumann's tweeter.
And I wonder if you tried to adjust the treble on the Neumanns. Could this be caused by your listening environment?
In short, because you are not him: If you compare the spinoramas you can see clear differences in sound power between i.e. the KH120 and KH150 vs. 8351. Genelec emitts more treble energy into the room, that's why they are often perceived as brighter, even though the on axis FR is the same. The difference should be smaller or irrelevant under near field conditions. No mystery there.