Abstract wallpapers are the safe, stylish default — no subject to get tired of, no busy detail fighting your icons, just colour and form. Gradients, flowing waves, geometric shapes and soft blurs sit quietly behind your workspace and tie your whole setup together.
They're also the easiest category to match to a colour scheme: pick a wallpaper that echoes your accent colour and the desktop suddenly looks designed rather than decorated. Each piece here is rendered at high resolution so the gradients stay smooth, with no banding, at 4K and above.