Dark Turquoise (#00CED1)

/* Background */
.element {
    background-color: #00CED1;
}

/* Text */
.element {
    color: #00CED1;
}

/* Border */
.element {
    border: 1px solid #00CED1;
}

/* Linear gradient to complementary */
.element {
    background: linear-gradient(
        to right,
        #00CED1,
        #D10300
    );
}

/* Radial gradient */
.element {
    background: radial-gradient(
        circle,
        #00CED1,
        #D10300
    );
}

// SCSS variable
$dark-turquoise: #00CED1;

// With RGB channels (useful for rgba() usage)
$dark-turquoise-r: 0;
$dark-turquoise-g: 206;
$dark-turquoise-b: 209;

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