Source/WebCore/html/shadow/meterElementShadow.css

/* use div# because the preprocessor doen't like # start */

div#inner {
    appearance: inherit;
    box-sizing: inherit;
    height: 100%;
    width: 100%;
}

div#bar {
    background: linear-gradient(to bottom, #ddd, #eee 20%, #ccc 45%, #ccc 55%, #ddd);
    height: 100%;
    width: 100%;
    box-sizing: border-box;
}

div#value {
    height: 100%;
    box-sizing: border-box;
}

div#value.optimum {
    background: linear-gradient(to bottom, #ad7, #cea 20%, #7a3 45%, #7a3 55%, #ad7);
}

div#value.suboptimum {
    background: linear-gradient(to bottom, #fe7, #ffc 20%, #db3 45%, #db3 55%, #fe7);
    height: 100%;
    box-sizing: border-box;
}

div#value.even-less-good {
    background: linear-gradient(to bottom, #f77, #fcc 20%, #d44 45%, #d44 55%, #f77);
    height: 100%;
    box-sizing: border-box;
}