.r{
    color: red;
}
.o{
    color: orange;
}
.g{
    color: yellow;
}
.G{
    color: green;
}
.b{
    color: blue;
}
.i{
    color: indigo;
}
.f{
    color: violet;
}

.regnbue{
    text-align: center;
}