They didn't call it a tractor beam at first.
They merely said the beam was holding them in place. It didn't look like a tractor beam either.
Yes they did, they specifically said they were caught in a "tractor beam" when it first appeared, and said "the tractor beam has released us" when it went away. I think you might have Emissary and Q Who mixed up. In Emissary it was blue and they didn't say what it was (but the same weapon shown there was also
specifically called a tractor beam in BOBW).
That's your point.
My point is that everything when radically green. Noticing a touch of green isn't the same as throwing a bucket of green paint on everything. That's what they did. The Ships turned green, green spot lights green shields, green control panels...
My point was "what became green that wasn't already green?" They didn't just indiscriminately dump green paint all over everything. Greens and blacks were already a defining characteristic, and they built on that.
The cube in QH was predominately black with a green glow coming from inside... so was the cube in FC. The green glow was even in the original concept art.
The torpedoes in QH and cutting beam in BOBW were green, so the Borg weaponry is green in FC.
Green control panels? Here they are in BOBW: http://memory-alpha.org/wiki/File:Borg_viewscreen.jpg