[Blackpool rocket]

Sometime over the past few months, someone here, possibly jezza? had some considerable knowledge about Poinsettia. Specifically the colouration of the leaves. Something to do with light levels?
Anyway, I have searched and have come up blank.
Any knowledge gratefully received.

Thanks.

[Yorkie]

Some info here: https://www.thespruce.com/poinsettias-keepers-or-compost-1403587

[Blackpool rocket]

Some info here: https://www.thespruce.com/poinsettias-keepers-or-compost-1403587

Thank you, that's very informative.