Since 1.14.1, the Iron Hoe texture's bottom portion of the stick uses the Dark Iron color, not the stick's normal wooden color, none of the other iron tools have this effect.

If you look at the image in attachments, youll see the entire "dark" side of the stick uses the dark iron color, not the dark wood color.

I do not believe this to be a feature, but more a small error with retexturing

Heres a large scale to see the difference in color between the wood and iron
(In the attachments)