I think it's hard to find an exact equivalent because Russian has a number of color words that are used mostly for one category of objects. For example, рыжий f

I think it's hard to find an exact equivalent because Russian has a number of color words that are used mostly for one category of objects. For example, рыжий for human or animal hair, русый for human hair, карий and болотный for eyes, смуглый for skin, etc. So when translating, you might pick the English equivalent for describing that type of object (рыжие волосы = red hair), but it doesn't feel quite right, because that same English word would be perfectly OK for describing the color of all sorts of unrelated things (and might imply a different shade when applied to those unrelated things!), and the original Russian word wouldn't be.