CSS 데모: text-decoration-color 데모 버튼을 클릭해 보세요!
selector {
    text-decoration-color: <color>
}
/* <color> 값 */
text-decoration-color: currentcolor;
text-decoration-color: red;
text-decoration-color: #00a0e9;
text-decoration-color: rgb(255, 255, 128);
text-decoration-color: rgba(255, 255, 128, 0.5);
text-decoration-color: transparent;

/* 전역 값 */
text-decoration-color: inherit;
text-decoration-color: initial;
text-decoration-color: revert;
text-decoration-color: revert-layer;
text-decoration-color: unset;
<p>텍스트 데코레이션 컬러 값이 blue입니다.</p>
p {
    text-decoration: underline;
    text-decoration-thickness: 3px;
    text-decoration-color: blue;
}
실제 적용 모습