The text and border will be green if your browser supports font smoothing.
.box { border: 4px solid blue; color: blue; } @supports (font-smooth: always) or (-webkit-font-smoothing: antialiased) { .box { border: 4px dashed darkgreen; color: darkgreen; } }
<div class="box"> The text and border will be green if your browser supports font smoothing. </div>