Odd child:
tr:nth-child(odd) { background-color:wheat; }

1 one
2 two
3 three
4 four
5 five

Even child:
tr:nth-child(even) { background-color:wheat; }

1 one
2 two
3 three
4 four
5 five

Every third child:
tr:nth-child(3n+1) { background-color:wheat; }

1 one
2 two
3 three
4 four
5 five
6 six
7 seven
8 eight
9 nine
10 ten

First child:
tr:first-child { background-color:wheat; }

1 one
2 two
3 three
4 four
5 five

Last child:
tr:last-child { background-color:wheat; }

1 one
2 two
3 three
4 four
5 five

First 3 children:
tr:nth-child(-n+3) { background-color:wheat; }

1 one
2 two
3 three
4 four
5 five

Last 3 children:
tr:nth-last-child(-n+3) { background-color:wheat; }

1 one
2 two
3 three
4 four
5 five

Nth child/last in group:
tr:nth-child(3n-1) { background-color:wheat; }

1 one
2 two
3 three
4 four
5 five
6 six
7 seven
8 eight
9 nine
10 ten

Test of adjacent selector.

This paragraph must be red.

And this must not.

This must be black.

Test of has-child and has-children

This paragraph must be blue.

And this must be red.

Test of has-child-of-type and only-of-type

This paragraph must be blue.

And this must be red.

And this must be green.

This paragraph must be purple.

And this must be purple too!

This paragraph must be green.

And this must be green too!