These are broad visual design styles that are common in commercial software, including websites. I have not named these styles.
Common sights: monochrome colour palette; layering provided mostly by solid black; generally flat interface; dithering used for shadows and greys; square corners.
Common sights: Light grey colour palette; strong border style depth cues on interface elements.
Common sights: Gradients to simulate convex surfaces; light effects like reflection and sun-bursts; visual effects to simulate soft or shiny plastic; soft/bright/approachable colour palettes.
Common sights: large, strong geometric sans-serif titles; centred titles; containers with rounded corners; low contrast between background and containers; titles made of emphasised and de-emphasised text colours; masonry container layout groups; vibrant imagery.
Common sights: rounded corners; smoked-glass-like transparency layering; low-contrast colour palette.
Common sights: simple, often monochrome user interface; relies on content for colour; puts the content first; large vold titles.
Common sights: slightly rounded corners; low-contrast structure colour palette; low-contrast typographic scale; thin lines and borders; low-contrast buttons; text-heavy.
Common sights: dark colour palette; cold to warm neon gradients; thin lines; glass effects; gradient background fills; structured container-based layout.
Common sights: bright, saturated colours; playful illustrations; thick borders; rounded corners; expressive typefaces; solid drop-shadows.
Common sights: monochrome colour palette; full width main title; fully justified main navigation; large text sizes; strong dividers between sections.