'Black' in the Bible

When he has leveled its surface,does he not then scatter black cumin and sow cumin?He plants wheat in rows and barley in plots,with spelt as their border.

Certainly black cumin is not threshedwith a threshing board,and a cart wheel is not rolled over the cumin.But black cumin is beaten out with a stick,and cumin with a rod.

I dress the heavens in blackand make sackcloth their clothing.

“Poor Jerusalem, storm-tossed, and not comforted,I will set your stones in black mortar,and lay your foundations in sapphires.