Robin Egg Blue (#00CCCC)

/* Background */
.element {
    background-color: #00CCCC;
}

/* Text */
.element {
    color: #00CCCC;
}

/* Border */
.element {
    border: 1px solid #00CCCC;
}

/* Linear gradient to complementary */
.element {
    background: linear-gradient(
        to right,
        #00CCCC,
        #FF9999
    );
}

/* Radial gradient */
.element {
    background: radial-gradient(
        circle,
        #00CCCC,
        #FF9999
    );
}

// SCSS variable
$robin-egg-blue: #00CCCC;

// With RGB channels (useful for rgba() usage)
$robin-egg-blue-r: 0;
$robin-egg-blue-g: 204;
$robin-egg-blue-b: 204;

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