In the hadith, “A group in the last of time will dye their hair black, like the crops of pigeons,” what is the meaning of “like the crops of pigeons”?

The questioner:
He says: Honorable Shaykh, may Allah grant you success, in the hadith what is the meaning of “like the crops of pigeons”? It means whiteness; that is, whiteness appears in it. You see those who dye their hair; the roots of the hair come out white because the hair grows longer every day, and something white emerges, so it becomes disfigured.

The Shaykh:
This is advice for the person.

The presenter:
Yes.

The Shaykh:
The poet says: Its top turns black, but its roots refuse [to do so], and there is no good in a branch if the root is corrupt.