kubernetes-handbook/gitbook/gitbook-plugin-alerts/style.css

.info {
    background: #eff5ff;
    border-color: #42acf3;
    color: #444;
}
.info strong {
    color: #42acf3;
}
.warning {
    background: #fcf8f2;
    border-color: #f0ad4e;
    color: #444;
}
.warning strong {
    color: #f0ad4e;
}
.danger {
    background: #fdf7f7;
    border-color: #d9534f;
    color: #444;
}
.danger strong {
    color: #d9534f;
}
.success {
    background: #f3f8f3;
    border-color: #50af51;
    color: #444;
}
.success strong {
    color: #50af51;
}