Cerulean Blue (#2A52BE)

/* Background */
.element {
    background-color: #2A52BE;
}

/* Text */
.element {
    color: #2A52BE;
}

/* Border */
.element {
    border: 1px solid #2A52BE;
}

/* Linear gradient to complementary */
.element {
    background: linear-gradient(
        to right,
        #2A52BE,
        #F1D58B
    );
}

/* Radial gradient */
.element {
    background: radial-gradient(
        circle,
        #2A52BE,
        #F1D58B
    );
}

// SCSS variable
$cerulean-blue: #2A52BE;

// With RGB channels (useful for rgba() usage)
$cerulean-blue-r: 42;
$cerulean-blue-g: 82;
$cerulean-blue-b: 190;

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