Red 6 on a roll sign

[jnewman]

I was riding the 1 train today, and I spotted this interesting route designator on the roll sign. What could it be for?
Sorry about the poor quality, it was my cell phone camera.

[Pelham]

That is a upside down # 9 Sign.

[jnewman]

Of course, my brain is fried
Just another thing that was wrong on the 7th Ave. Subway today...
Oh, well.
Sorry.

[MACTRAXX]

JN and Pelham: I looked at this one myself yesterday and then it hit me...Number 9,Number 9,The Watusi,The Twist....it is the Beatles song coming out...that is simply an upside down #9 roll sign. On the newest IRT equipment with the LED front # designation I wonder if it would have been possible to add the color green for #s 4,5 and 6;purple for the 7 and the digits 8 and 9 for future routes-color to be determined. MACTRAXX

[Gerry6309]

A red 6 would be a towerman's nightmare! A red 4 is just a bad dream. Now a red 5 or a green 2 is within the realm of possibility.

[uhaul]

Gerry6309, I do not understand why a red 6 would be a towerperson's nightmare and a red 4 a bad dream. Also, what is up with the red 5 or a green 2 being within the realm of possibility?
Is this some lingo I have no clue about?

9/11/01
9/11/07

[UpperHarlemLine4ever]

Talking about the colors of the LED's, why can't they make the LED on the front of the train, the color of the line ie, 1, 2, 3 Red, 4, 5, 6 Green and 7 Purple? Is it a cost cutting factor, cause it certainly not a technology issue.