I had a Raleigh (sold as frameset only) that had a similar fade paint job, they referred to it as "shark gray fade" or something, and was 2 shades of gray: light and dark.
It really fooled the eye since the "shadow" of the dark gray paint wasn't where it should have been from the light source. I got more than one comment from someone who couldn't tell if his brain was in a feedback loop when he looked at my bike.