short-day treatment

I bought my first poinsettia at the end of last year. As the weather warms up, new green leaves grow. Two weeks have passed since I learned that short-day treatment is necessary to turn the leaves red. As expected, it hasn't turned red yet, but if you look closely, you can see that the veins of the leaves are a little red! I hope this is the effect of short-day treatment😃✨🌿