We are in Sicily now, have been for a couple weeks, in about 5 different locations.
I guess the first question is what is your concern? Are you concerned restrictions may impact your trip? Or are you more concerned about the covid risk to you?
As for restrictions, a year ago, "Yellow" carried several more restrictions that would impact you as a traveler; however, most of those (like limited hours for restaurants, reduced capacity in reastaurants, etc.) have been stripped out, and the main one for most travelers is the wearing a mask outdoors. However, enforcement from a strict perspective is not done. We will not wear a mask if we are separated from others, but opt to put it on if we encounter a crowded street, a market, or other place that has a density of people. We are often though in the minority with masks on, and Police are not being strict on enforcement. Indoors is different, nearly everyone complies, or at least in dealings with the public.
If your concern is about danger to your health, then consider a couple factors. Italy's overall covid rate is going down, they appear to be declining from the recent peak. Further, the cases per 100,000 are running about 4000 to 6000, there are only two States in the US (Hawaii and Vermont) that have lower rates, and likely the State you live in is easily double that of Italy and Sicily.
Given better enforcement of Covid measures (Indoor masks, masks on public transport, etc.) and the lower rate, you are likely safer in Sicily than where you are, and by your trip, it is very likely Sicily will no longer be Yellow.
We have benefited however from being able to eat nearly every meal outdoors, at the time of your trip, weather may not allow that, but possibly, that may add a factor we are not facing.