Dark Byzantium (#5D3954)

/* Background */
.element {
    background-color: #5D3954;
}

/* Text */
.element {
    color: #5D3954;
}

/* Border */
.element {
    border: 1px solid #5D3954;
}

/* Linear gradient to complementary */
.element {
    background: linear-gradient(
        to right,
        #5D3954,
        #39814B
    );
}

/* Radial gradient */
.element {
    background: radial-gradient(
        circle,
        #5D3954,
        #39814B
    );
}

// SCSS variable
$dark-byzantium: #5D3954;

// With RGB channels (useful for rgba() usage)
$dark-byzantium-r: 93;
$dark-byzantium-g: 57;
$dark-byzantium-b: 84;

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