The border-top-color property in 
In order to use the
border-top-colorproperty, we must use theborder-styleor theborder-top-styleproperty. This is because the color is only changed if you have a border.
border-top-color: color|transparent|initial|inherit;
color: This is used to set the color of the top border.
transparent: This is used to specify that the color of the border should be transparent.
initial: This is used to set the value to its default value.
inherit: This is used to inherit property from its parent value.