Alternating POST Colors?

[Dudeness]

How can I create alternating row post colors? For example post 1. has a gray row background and post 2. has a green background.

The avatars and such should stay on the left side. I found ways to do this for the home and threads list but not posts inside threads.

For example see this thread. It has alternating light and darker gray post colors.

Can anyone please tell how to do this?

[Dismounted]

You can edit the postbit/postbit_legacy template and use a conditional to decide on a colour (and insert the appropriate CSS/HTML).

<if condition="$post['postcount'] % 2">POST IS EVEN<else />POST IS ODD</if>

[Dudeness]

Okay well I'm not a savvy html coder though. Can I paste that in the postbit and what else needs to be added?