But in this digital era, I doubt there are still superstitions like that believed by gamblers, it just that in the 5 things you mentioned I still believe in red as bringer of luck and of course this belief has become kind of culture for some regions and certain groups.
Color red is indeed symbol of courage and strength, even the Chinese consider it bringer of prosperity and luck and I in roulette game always choose red over black in betting on color selection for the table in numbers and it true that red brings victory more often.