Other Colors and Color Metafields

In addition to Variant Redirect and Colors features, which you can use to display a Color Swatch there now is a direct way to implement this without cluttering the variants.

Example showing two products, one in color black and one in red

First set the "Color" Metafield for all relevant products correctly (also see colors). Then add all the products to each other's "Other Colors" Metafield.

example