<style>
.test:nth-child(odd)
{
color:Blue;
}
.test:nth-child(even)
{
color: Red;
}
.test:nth-child(2)
{
color: Green;
}
</style>
<div class="test">
<p>
1
</p>
<p>
2
</p>
</div>
<p class="test">
1
</p>
<p class="test">
2
</p>
<p class="test">
1
</p>
<p class="test">
2
</p>