That site hurts my eyes.

Blimey, you're not kidding.

Just for your own amusement..... I followed the link so that I could come back and say how wrong you were. My head ache is your payoff!!!!!! :)

I guess the site is themed resembling Hercules graphics terminal, or some like that.

Pointless minutiae:

Hercules was a video card, not a terminal. The color for monochrome is defined by the monitor, of course. Green phosphor CRTs were quite common in the IBM PC world (starting with IBM's original 5151 monitor I think), but for terminals actually used on Unix machines other colors were more typical. The VT-100 series were blue, I believe; and later DEC terminals went with amber. White was reasonably common. I don't think I ever used a real terminal on a Unix box with a green phosphor.

My mistake, i was remembering old pc 8086 with hercules card and green monitor. Also that look resembled the ibm3151 green terminals, but i liked more the yellowish ones.

Yep, green on black, classical nix terminal. :) Even Matrix uses this colour scheme: https://www.youtube.com/watch?v=0PxTAn4g20U

Good old times piloting a cp500. I remember the chicken game crossing the street! That was epic!