Napier Green (#2A8000)

/* Background */
.element {
    background-color: #2A8000;
}

/* Text */
.element {
    color: #2A8000;
}

/* Border */
.element {
    border: 1px solid #2A8000;
}

/* Linear gradient to complementary */
.element {
    background: linear-gradient(
        to right,
        #2A8000,
        #AC01FF
    );
}

/* Radial gradient */
.element {
    background: radial-gradient(
        circle,
        #2A8000,
        #AC01FF
    );
}

// SCSS variable
$napier-green: #2A8000;

// With RGB channels (useful for rgba() usage)
$napier-green-r: 42;
$napier-green-g: 128;
$napier-green-b: 0;

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