how to change border color in css code example

Example 1: how to blur background color in css

background: rgba(255,255,255,0.5);
backdrop-filter: blur(5px);

Example 2: border color css

border: 1px solid #000000;

Example 3: border color css

border: 1px;
border-color: #3581fc;

Example 4: add color to border css

div {border-color: coral;}