There may be red daylilies that are similar in flower size, plant size, and flower shape to 'Stella de Oro' and maybe even related, but I wouldn't categorize them as red versions of Stella. "Stella de Oro' is registered as gold so can only be gold and still be 'Stella de Oro'. Interestingly we commonly abbreviate 'Stella de Oro' to 'Stella' but there actually is a daylily registered only as 'Stella', dates back to 1939.
Incidentally, Ruby Stella is not an actual cultivar name, according to the US patent office, it's real cultivar name is 'Berrub' but it is sold under the trade name Ruby Stella.
I don't want to be a pessimist but there are now over 82,000 different daylilies registered and identifying one from a picture is likely to be difficult if not impossible unless there is something very distinctive about it.
