British Racing Green (#004225)

/* Background */
.element {
    background-color: #004225;
}

/* Text */
.element {
    color: #004225;
}

/* Border */
.element {
    border: 1px solid #004225;
}

/* Linear gradient to complementary */
.element {
    background: linear-gradient(
        to right,
        #004225,
        #84003A
    );
}

/* Radial gradient */
.element {
    background: radial-gradient(
        circle,
        #004225,
        #84003A
    );
}

// SCSS variable
$british-racing-green: #004225;

// With RGB channels (useful for rgba() usage)
$british-racing-green-r: 0;
$british-racing-green-g: 66;
$british-racing-green-b: 37;

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