Red (RYB) (#FE2712)

/* Background */
.element {
    background-color: #FE2712;
}

/* Text */
.element {
    color: #FE2712;
}

/* Border */
.element {
    border: 1px solid #FE2712;
}

/* Linear gradient to complementary */
.element {
    background: linear-gradient(
        to right,
        #FE2712,
        #FDFFFF
    );
}

/* Radial gradient */
.element {
    background: radial-gradient(
        circle,
        #FE2712,
        #FDFFFF
    );
}

// SCSS variable
$red-(ryb): #FE2712;

// With RGB channels (useful for rgba() usage)
$red-(ryb)-r: 254;
$red-(ryb)-g: 39;
$red-(ryb)-b: 18;

// Usage
.element {
    background-color: $red-(ryb);
    color: rgba($red-(ryb)-r, $red-(ryb)-g, $red-(ryb)-b, 0.8);
}