basic.css

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    background-color: #ffeb3b;
    color: white;
    font-size: xx-large;
    text-align: center;
    font-family: fantasy;
}

.container div:nth-of-type(1) {
    background-color: #00BCD4;
}

.container div:nth-of-type(2) {
    background-color: #FF5722;
}

.container div:nth-of-type(3) {
    background-color: #CDDC39;
}

.container div:nth-of-type(4) {
    background-color: #9E9E9E;
}

.container div:nth-of-type(5) {
    background-color: #607D8B;
}

.container div:nth-of-type(6) {
    background-color: #FFC107;
}