"This actress has red hair."
Translation:Ця актриса має руде волосся.
Because червоний means literally red colour. Рудий means "dark orange".
In English "red" is used to denote the colour of fur and hair, even though it's obviously orange, because it's an old word from the times when people didn't have a word for orange as a separate colour.
Or waaaaaaaaait, do you mean that a person literally has red hair, like, as red as blood, because they dyed it that way? :D And "She has red hair" can mean that, so it also can be translated as "червоний"? :D
That's cool and IS a correct translation. But it won't be accepted here, because this way one can't see whether the person did learn the word "рудий" or not. It would look like people are just literally translating "red" to "червоний" thinking that's how they can call "orange" hair...