Dark Sienna (#3C1414)

/* Background */
.element {
    background-color: #3C1414;
}

/* Text */
.element {
    color: #3C1414;
}

/* Border */
.element {
    border: 1px solid #3C1414;
}

/* Linear gradient to complementary */
.element {
    background: linear-gradient(
        to right,
        #3C1414,
        #146464
    );
}

/* Radial gradient */
.element {
    background: radial-gradient(
        circle,
        #3C1414,
        #146464
    );
}

// SCSS variable
$dark-sienna: #3C1414;

// With RGB channels (useful for rgba() usage)
$dark-sienna-r: 60;
$dark-sienna-g: 20;
$dark-sienna-b: 20;

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