Not sure what the wattage works out to (cause too lazy to calculate) but I'm running Vero29s @ 100w ... canopy a few inches from the lamps... no bleaching just don't let the cola's sit right under a COB and yer good.
How much total wattage, how much surface, tent or no tent?
Bleaching also depends on ppfd.
One 100w COB, 2"x 2" area-no tent, no bleaching below 12".
Two 100w COB's, same area but in a tent, most probably bleaching below 12".
Reflective walls makes also a huge difference.
And at last, it depends on the used strains, some strains are more sensitive to high irradiation than other.
I've ~370w, a 9sft' tent(white, 28x 48"), 8 COB's@1050mA + 24 OsramOslon SSL80 hyperred, ~900-1000μMol/s/0,84m² and most of the strains showing signes of light stress below 16".
At 20" and above no lightstress!