Sorry, I can not type chinese now " M0 l2 I* t& @& Y' {- }7 x 5 E ?8 n* _! v6 wBut, I put the poinsettia in a seperate room which should have more than 10hrs black time. Maybe it need more sun light?
at least 10hrs darkness, you can treat it 10~14hrs or longer ,it does not a matter, just a couple of hrs of sun light. and hopefully it can change corlor 3 weeks later till x-mas day.