Medium Aquamarine (#66DDAA)

/* Background */
.element {
    background-color: #66DDAA;
}

/* Text */
.element {
    color: #66DDAA;
}

/* Border */
.element {
    border: 1px solid #66DDAA;
}

/* Linear gradient to complementary */
.element {
    background: linear-gradient(
        to right,
        #66DDAA,
        #EFCBDA
    );
}

/* Radial gradient */
.element {
    background: radial-gradient(
        circle,
        #66DDAA,
        #EFCBDA
    );
}

// SCSS variable
$medium-aquamarine: #66DDAA;

// With RGB channels (useful for rgba() usage)
$medium-aquamarine-r: 102;
$medium-aquamarine-g: 221;
$medium-aquamarine-b: 170;

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