Dark Orange (#FF8C00)

/* Background */
.element {
    background-color: #FF8C00;
}

/* Text */
.element {
    color: #FF8C00;
}

/* Border */
.element {
    border: 1px solid #FF8C00;
}

/* Linear gradient to complementary */
.element {
    background: linear-gradient(
        to right,
        #FF8C00,
        #0073FF
    );
}

/* Radial gradient */
.element {
    background: radial-gradient(
        circle,
        #FF8C00,
        #0073FF
    );
}

// SCSS variable
$dark-orange: #FF8C00;

// With RGB channels (useful for rgba() usage)
$dark-orange-r: 255;
$dark-orange-g: 140;
$dark-orange-b: 0;

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