Ameixa is a Material Design inspired icon theme aiming to provide a
consistent and minimalistic look to your device. This theme supports
mainly FLOSS apps icons. There is also a black and white version
available https://f-droid.org/packages/org.xphnx.ameixamonochrome.

Suported launchers:

Trebuchet
Kiss
Nova
Apex
Holo
Asus
Adw
and many more