Cadmium Yellow (#FFF600)

/* Background */
.element {
    background-color: #FFF600;
}

/* Text */
.element {
    color: #FFF600;
}

/* Border */
.element {
    border: 1px solid #FFF600;
}

/* Linear gradient to complementary */
.element {
    background: linear-gradient(
        to right,
        #FFF600,
        #0009FF
    );
}

/* Radial gradient */
.element {
    background: radial-gradient(
        circle,
        #FFF600,
        #0009FF
    );
}

// SCSS variable
$cadmium-yellow: #FFF600;

// With RGB channels (useful for rgba() usage)
$cadmium-yellow-r: 255;
$cadmium-yellow-g: 246;
$cadmium-yellow-b: 0;

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