border color css

CSS
Syntax:
div {border-color: red;} 

Definition and Usage:
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The border-color property sets the color of an element's four borders. This property can have from one to four values.

If the border-color property has four values:
border-color: red green blue pink;
  top border is red
  right border is green
  bottom border is blue
  left border is pink

If the border-color property has three values:
border-color: red green blue;
  top border is red
  right and left borders are green
  bottom border is blue

If the border-color property has two values:
border-color: red green;
  top and bottom borders are red
  right and left borders are green

If the border-color property has one value:
border-color: red;
  all four borders are red

Note: Always declare the border-style property before the border-color property. An element must have borders before you can change the color.
Source

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