So Signal was not lying, trees really start changing a little later in St.John's hehe.
According to this site, which is regularly updated, we are starting to see colours in pretty much all of Ontario. Some areas have not been updated and are most likely inaccurate by now (Eastern Ontario, Prince Edward County).
Strangely enough the only parks that are allegedly 100% green are on Lake Huron. Weathly Park in Extreme Southern Ontario is marked as 100% green, but the description says that a little bit of yellow and red is now visible. Of course things are different in urban areas.
https://www.ontarioparks.com/fallcolour