WooSwatches makes variation selection much clearer.

WooSwatches – Color or Image Variation Swatches for WooCommerce replaces the standard dropdown menu used for variable product options with visual swatches in colour, image or label form. This means a customer can click on a coloured square, image thumbnail or label instead of choosing from a plain select list — making it far easier to see at a glance what size, colour or pattern a product has. You can set swatches globally, so they apply automatically whenever those attributes are used, or adjust them per product if needed. It also supports different shapes and sizes (square or round), works on mobile devices, and displays swatches on shop, archive, and product pages.