UXpedia
Style Tiles

While wireframes are trying to represent layout without design, style tiles are meant to show how the visual elements look without considering the page layout.
This is also an obvious split point in UX and UI design — although those two areas are like brothers — the best way to focus laser-sharp on each areas and completely separate the two main questions — ‘Where it should be?’ and ‘How it should look?’ — is to deal with those two things separately.
Another benefits of creating style tiles separate to page layouts is to help the stakeholders to focus their feedback on the visual elements only.
I personally love this approach, it doesn’t only give the UI designer a better focus on the small details and opens a path to bunch of visual element variations, but also helps creating a consistent visual appearance.