There's more to it?

There must be a temperature element too?
On the 26th Nov. Jerra's looked like this.
On the 23rd of October I said:-
"No sign of reddening yet - NOT yet expected.  I suspect I've not been jailing it long enough yet."
At which point clicky said:-
"Bright light in daytime and 14 hours complete dark should redden them in 4 weeks."
NOW mine has had in excess of 14 daily hours of dark, TOTAL dark, in a box, covered by black plastic since before the 23rd Oct (A month ago now) - WHERE's the red?


Plan B:-
Computer shack at about 20-21˚C day time.
The Box at about 11-12˚C over night; let's see if temperature is a factor.