First things first: I really love your Icelander theme! :)
I create a website for a charity and they don’t want a grey gleam on their header-image. You can see it on the main page that blue sky (and everything else) becomes grey(-ish). I’ve looked through the documentation, the support forum and the internet itself but haven’t found a clou to get rid of it.
I’m only able to find the background opacity slider for the footer.