Sets or gets the foreground color of an element.
The foreground color value is a string representing an rgba color in one
of the following formats:
- "red": One of 140 predefined color names.
- "#FF0000": A hexadecimal rgb color value.
- "rgb(255,0,0)": An rgb() function color value.
- "#FF000000": A hexadecimal rgba color value.
- "rgba(255,0,0,1.0)": An rgba() function color value.
This style can be used with the following elements: