If you've ever wanted to do something like set the borders on a container to the same color as the text within it you can easily do it using currentColor.

currentColor can be used for anything that accepts a color value like box-shadow, background-color, etc.

The CSS

.parent {
    color: red;
}

.child {
    border: solid 3px currentColor;
}

The Demo

Browser Support

CSS currentColor has pretty good browser support working in all modern browsers. Not supported in ie8 and below.