Name of colors

I have a color in Styleguide named `#black8` but a color property of a shadow or a border have `undefined` name.
Example of using:
```js
function cgColor(color, useColorNames) {
    if (useColorNames && color.name) {
        return "UIColor." + color.name + ".cgColor\n"
    }
    return uiColor(color.r, color.g, color.b, color.a) + ".cgColor\n"
}
```