Orange Red (#FF4500)

/* Background */
.element {
    background-color: #FF4500;
}

/* Text */
.element {
    color: #FF4500;
}

/* Border */
.element {
    border: 1px solid #FF4500;
}

/* Linear gradient to complementary */
.element {
    background: linear-gradient(
        to right,
        #FF4500,
        #00BAFF
    );
}

/* Radial gradient */
.element {
    background: radial-gradient(
        circle,
        #FF4500,
        #00BAFF
    );
}

// SCSS variable
$orange-red: #FF4500;

// With RGB channels (useful for rgba() usage)
$orange-red-r: 255;
$orange-red-g: 69;
$orange-red-b: 0;

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