.text-box h3:first-of-type {
    color: pink;
}

#greycol {
    color: grey;
}

.text-box div > p {
    color: red;
}

.text-box p.yellow {
    color: yellow;
}

.text-box > p:not(#greycol):not(.yellow):not(:first-of-type) {
    color: green;
}