colour sections appear to be leaking -unfixed!

I thought this was fixed before, but perhaps it just wasn’t happening as obvious as it was previously. However, now again this problem is rearing its head in multiple locations and I can’t seem to make much sense of it. Basically the colour sections with a defined background image or colour will leak that background beyond the section into whatever other content exists below. This can stop the moment I introduce another colour section, which will then exhibit the problem further down the page.