A few things:
1. You have a tiny slice at the left of your header image which links back to the main page, but it doesn't extend to the full image. Get the header image to link, and remove the piece on the left.
2. The text beneath the header image and before the content takes up WAY too much visual space on the page.
3. The navigation beneath the header image needs to contrast a bit more with the background, and I think it would work better as a footer based off of the content it links to.
4. You should have a more obvious visual queue for the user to distinguish between posts. Maybe a larger break between them, or perhaps a simple line beneath each post. As is, they sort of blend into one another.
Other than that the color scheme and layout overall seems good :)