I have very good color acuity... and yes I see the 6 in the pattern. I also know that when I see lights flickering that no one else sees, there is a good chance that there may be a problem somewhere... such as a motor overloading or a circuit failing. Or simply a monitor poorly tuned to a video card.
Unfortunately I see that flicker all the time in our house when the new HE washer is on... which means it is putting a terrible pulsed load on our electrical system... which no doubt will lead to problems in the future.
Oh and if you want to test your color acuity... yes, there is a web site for that too.