border-top-color: yellow;
border-bottom-color: navy;
border-left-color: lime;
border-right-color: teal

border-top-color: #33ff66;
border-bottom-color: #006600;
border-left-color: #33ff00;
border-right-color: #336633

border-top-color: red;
border-bottom-color: blue;
border-left-color: transparent;
border-right-color: transparent