Unless the indigenous peoples outnumber the colonialists (Italian or German) by a large margin, and are willing to try and "smother" them with their bodies, a successful uprising is not in the cards. Rebels with small arms against folks with advanced weapons, and gas, who are simply willing to kill men, women, and children in an area of resistance, won't succeed. Its all well and good to be fish in a sea as Mao opined, however if your enemy is willing to drain the sea to kill all the fish, sharks and guppies, you're screwed. The Italians used mustard gas against the Ethiopians in the 30s, and we know how that turned out. Saddam used nerve gas against the Kurds, and that did not end well for them either until the Americans intervened.
Mussolini was not as ruthless as the Nazis, but the Italians were ruthless "enough" when they felt it was necessary. Heck, even the British used mustard in the 20s against some rebels in Iraq.
Especially in Italian areas, being an indigene is probably not the life of Hell that it would be if the Nazis were in charge.