Steel Blue (#4682B4)

/* Background */
.element {
    background-color: #4682B4;
}

/* Text */
.element {
    color: #4682B4;
}

/* Border */
.element {
    border: 1px solid #4682B4;
}

/* Linear gradient to complementary */
.element {
    background: linear-gradient(
        to right,
        #4682B4,
        #E2B086
    );
}

/* Radial gradient */
.element {
    background: radial-gradient(
        circle,
        #4682B4,
        #E2B086
    );
}

// SCSS variable
$steel-blue: #4682B4;

// With RGB channels (useful for rgba() usage)
$steel-blue-r: 70;
$steel-blue-g: 130;
$steel-blue-b: 180;

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