Sets or gets the border color of an element.
The border 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: