negritize
/ˌnɛɡrɪˈtaɪz/Definitions
1. verb
to darken or add a dark tint to (something)
“The artist decided to negritize the painting to give it a dramatic effect.”
2. verb
to make or become black or darker
“The coffee will negritize over time if left in the air.”
3. noun
a process or result of negritizing something
“The negritization of the painting was a deliberate artistic choice.”