Saint Patrick Blue (#23297A)

/* Background */
.element {
    background-color: #23297A;
}

/* Text */
.element {
    color: #23297A;
}

/* Border */
.element {
    border: 1px solid #23297A;
}

/* Linear gradient to complementary */
.element {
    background: linear-gradient(
        to right,
        #23297A,
        #D1C523
    );
}

/* Radial gradient */
.element {
    background: radial-gradient(
        circle,
        #23297A,
        #D1C523
    );
}

// SCSS variable
$saint-patrick-blue: #23297A;

// With RGB channels (useful for rgba() usage)
$saint-patrick-blue-r: 35;
$saint-patrick-blue-g: 41;
$saint-patrick-blue-b: 122;

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