Changing the background and text colour of posts on the homepage

Hi –

For reference, the site I’m working on is theparapod.com

Posts on the homepage aren’t all appearing the same – the first post you see is white text on black, the second is black text on white.

I want all of the posts to show up on the first page in the same way as the top one – white text on black.

I can’t work out what in the theme code needs to be changed to make this the case.

Any help is greatly appreciated!