I also could have put money that this thing was in technicolor. B/W is more tolerable than my eyethrobbing memories.
Anyway the actually worst I've ever seen was something called Carthage in Flames which was mindnumbingly dull yet features unconvincing romance AND unconvincing sword fights. I passed out during the movie. Oooh look it's on YouTube for free! https://youtu.be/UM5EDpftGsw