How to Add Color Swatches in Shopify Force Theme

Force can render a "Color" (or similarly named) variant option as visual swatches rather than a plain text dropdown — a native feature, not an app add-on.

Steps

Make sure your product's color option is actually named Color (or another name Force recognizes for swatches) under that product's variants.
In your Shopify admin, go to Online Store > Themes and click Customize on Force.
Open a product page and select the Product information section, then find the variant picker's display setting.
Set the color option's display style to Swatch.
Assign an actual color or image to each variant value — go to Settings > Product variants or the specific option's settings depending on how your store is set up.
Click Save.

Swatches only render correctly once each variant value has a real color or image assigned — an unassigned value falls back to plain text.