There is no "proper" color for a car for a female; just as there is no proper color for a car for a male. Whatever color appeals to you is the most appropriate color for you. 55 years ago, Dodge produced a car called the "La Femme." If my memory is correct, it was only available in pink. But very few of them were sold. Even that long ago, women preferred to make such decisions based on their personalities and sense of taste; rather than on what some jerk in a marketing department decided they "ought" to like.
Today, some women choose car colors to match the color of their hair; others choose a color that is popular, while others choose a color like white or beige that will not draw undue attention. Some women choose a flaming red car in order to attract males (in that case, it will often be a convertible). And some affluent, scheming women choose a car model that is most popular with men; typically a Chevy Corvette or Ford Mustang; or a Dodge Challenger for the most daring who desire a cutting edge image (but in order for such a car to remain credible with male enthusiasts at close range; it MUST have a stick shift).
There are a few car colors which seem to only be bought by racers or aggressive drivers. The most obvious of those are bright yellow or orange. A few years ago, we began to notice an increasing number of new black cars. I find this unsettling; because there are so many attractive car colors which can be bought, and because I associate black with depression.
But you can often discover uncommon car colors which fit you better than the ones that you usually see on the street. If you are shopping for a new car; ask to see the catalog of available colors. There are often colors in those catalogs which are not on the dealer's lot. If you want a car in one of those colors, be sure to get the name of it. The dealership can either order it for you; or check their computer listings to see which other dealers have one; and then have it transferred to their lot. Or you can phone other dealerships for that brand on your own and ask whether they have one in that color.