Yes...

Green for GO
Red for Stop.......

Except in Stravaland... where one uses RED for GO.

I find Strava is oddly designed. To get it to do something, I have to hit "Feed" then "Record Activity" (little tiny line), then "the RED button".

Ahh, changed the default screen so I get the red go button when I open Strava. Still, a bit odd. Perhaps they have half the features turned off, but to give an average speed, but no instantaneous speed???? And only recognizes HR monitors bought through their own store

I think RideWithGPS recently updated their website, and the best features such as planning a ride are now well buried.