Davy Grey (#555555)

/* Background */
.element {
    background-color: #555555;
}

/* Text */
.element {
    color: #555555;
}

/* Border */
.element {
    border: 1px solid #555555;
}

/* Linear gradient to complementary */
.element {
    background: linear-gradient(
        to right,
        #555555,
        #555555
    );
}

/* Radial gradient */
.element {
    background: radial-gradient(
        circle,
        #555555,
        #555555
    );
}

// SCSS variable
$davy-grey: #555555;

// With RGB channels (useful for rgba() usage)
$davy-grey-r: 85;
$davy-grey-g: 85;
$davy-grey-b: 85;

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