Charleston Green (#232B2B)

/* Background */
.element {
    background-color: #232B2B;
}

/* Text */
.element {
    color: #232B2B;
}

/* Border */
.element {
    border: 1px solid #232B2B;
}

/* Linear gradient to complementary */
.element {
    background: linear-gradient(
        to right,
        #232B2B,
        #332323
    );
}

/* Radial gradient */
.element {
    background: radial-gradient(
        circle,
        #232B2B,
        #332323
    );
}

// SCSS variable
$charleston-green: #232B2B;

// With RGB channels (useful for rgba() usage)
$charleston-green-r: 35;
$charleston-green-g: 43;
$charleston-green-b: 43;

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