Rubik Variant Images Theme Compatibility

Rubik Variant Images on Underground Themes: Testament, Icon, Vantage & More (2026)

April 17, 2026

Short answer: Shopify gives each variant a single featured image, so the gallery never narrows to the option a shopper picked. Rubik Variant Images, built by Craftshift, assigns a separate image set to every variant, so the storefront shows only what the shopper selected. Free to install, 5.0 stars across 436 reviews.

Underground is a Shopify theme studio based in Tunbridge Wells, UK. They have built 9 themes over the years, and some of them are genuinely popular. Testament alone has 399 reviews and a 96% positive rating at $350. Icon sits at 369 reviews. Mr. Parker has been around long enough to collect 207. These are not hobby projects.

But here is the thing every Underground theme user eventually hits: Shopify only assigns one image per variant. You pick “Navy” on a Testament product page and the featured image swaps, sure. The other 14 photos from every other colorway? Still sitting there in the gallery. Your customer scrolls past “Burgundy” and “Sage” lifestyle shots wondering if they even selected the right variant.

Rubik Variant Images works on all 9 Underground themes. We have native selector code for each one. Assign multiple images per variant, filter the gallery instantly on selection, and add color or image swatches that render inside Shadow DOM so they never conflict with Underground’s CSS.

Underground themes: who makes them

Underground is a UK-based studio in Tunbridge Wells. They have been building Shopify themes since the early days of the theme store, and their catalog spans fashion (Fashionopolism, Pose), general retail (Testament, Icon), food and beverage (Foodie), industrial (Forge), and everything in between. Some of these themes predate Online Store 2.0 and have been updated over time, while others like Drop are newer entries.

What they share: custom variant picker markup that differs from Dawn-based themes. We wrote dedicated selector code for Underground themes so Rubik can detect and replace their variant pickers correctly. This matters because generic apps that only look for Dawn-style selectors tend to break on these themes (or just quietly do nothing, which is arguably worse).

Testament ($350, 399 reviews, 96%)

Testament is Underground’s most reviewed theme. 399 reviews and a 96% positive rating is genuinely impressive for a paid Shopify theme. It is designed for large catalogs, fashion stores, and brands with big product ranges. Multi-column layouts, heavy use of product media, and a sticky product form on desktop.

The variant picker in Testament uses custom radio inputs with Underground’s own wrapper markup. We support it natively. When you install Rubik, the app detects Testament and wires up the correct selectors automatically. No code edits needed.

What Rubik adds to Testament: assign 5, 10, or 20 images to each color variant and the gallery filters down to only those images when a customer picks that color. Add image swatches showing actual product thumbnails, or color circle swatches for a cleaner look. Everything renders inside Shadow DOM, so Testament’s existing CSS does not interfere.

Fashionopolism ($350, 252 reviews)

Fashionopolism is the fashion-first theme. Full-width imagery, editorial layouts, lookbook sections. At $350 with 252 reviews, it is clearly popular with clothing and accessories stores. The name sort of gives it away.

Fashion stores are exactly where variant image filtering matters most. Think about it: a dress available in 8 colors with 4 lifestyle shots per color means 32 images in one gallery. Without filtering, customers see all 32 regardless of which color they selected. That is confusing and, honestly, kind of lazy-looking for a $350 theme investment.

Rubik fixes this on Fashionopolism. Select “Emerald” and only the 4 emerald photos appear. We also support multiple options, so if you have Color + Size + Material, each combination can show its own set of images.

Icon ($250, 369 reviews)

Icon has 369 reviews, making it Underground’s most-reviewed theme by raw count. Priced at $250, it sits below Testament and Fashionopolism but clearly delivers. It is a versatile theme that works for a wide range of store types, from electronics to home goods.

One thing we noticed when testing Icon: the product page media gallery has a slightly different DOM structure than Testament. Not a big deal from a merchant perspective (you would never know), but it is the kind of thing that breaks apps that assume every theme works like Dawn. We handle Icon’s gallery structure natively.

Drop ($250, 19 reviews)

Drop is one of Underground’s newer themes. Only 19 reviews so far, priced at $250. It appears to be designed for product drops and limited releases, with countdown timers and scarcity features baked in.

Even with a small review count, Drop still uses Underground’s custom variant picker pattern. Rubik recognizes it. Install, enable the embed, assign images, done.

Vantage ($150, 230 reviews)

Vantage is Underground’s most affordable theme at $150, and 230 reviews means a lot of stores are running it. It is a solid general-purpose theme. Nothing flashy, just well-built.

Why does this matter? Because $150 themes attract merchants who are watching their budget, and those same merchants are the ones who really feel the pain of Shopify’s “one image per variant” limitation. You paid $150 for your theme. Are you going to pay a developer $500 to hack variant image filtering into the Liquid code? No. That is what apps are for.

Rubik’s free plan lets you test on one product before committing. Try it on Vantage, see if you like the result, then scale up.

Foodie ($180, 22 reviews)

Foodie is purpose-built for food and beverage stores. Recipe sections, ingredient highlights, that sort of thing. 22 reviews at $180.

Food stores often use variants for flavors or sizes. A protein powder in Chocolate, Vanilla, Strawberry, and Unflavored, each with unique packaging photography. Rubik assigns the correct packaging shots to each flavor variant. Customers see Chocolate packaging when they pick Chocolate. Simple. But Shopify does not do this out of the box, and it is honestly baffling that they still have not fixed it in 2026.

Forge ($180, 15 reviews)

Forge is designed for industrial and tools-related stores. Bold typography, dark color options, rugged aesthetic. 15 reviews at $180. Smaller user base, but Rubik supports it just the same.

Industrial products with finish options (Matte Black, Brushed Steel, Chrome) benefit heavily from variant image filtering. Each finish photographs differently under studio lighting, and showing the wrong finish creates the wrong expectations. Returns follow.

Mr. Parker ($160, 207 reviews)

Mr. Parker is one of Underground’s older themes. 207 reviews at $160. It has been around for years and has a loyal following. The design is clean, slightly vintage-leaning, works well for lifestyle brands.

Older themes sometimes have quirks in their variant picker JavaScript. We have tested Mr. Parker thoroughly and Rubik integrates cleanly. If you are running Mr. Parker and debating whether to switch themes just to get variant image filtering, don’t. Install Rubik instead.

Pose (retired)

Pose is no longer available in the Shopify Theme Store, but stores that already purchased it can still use it. If you are running Pose, Rubik still works. We keep support for retired themes in our codebase because merchants should not be punished for running a theme they already paid for.

That said, if Pose is giving you other problems unrelated to variant images, it might be time to look at a newer Underground theme like Testament or Icon.

Rubik Variant Images theme compatibility with all popular Shopify themes

All Underground themes at a glance

Here is every Underground theme with pricing, review counts, and Rubik support status:

Theme	Price	Reviews	Rating	Rubik support
Testament	$350	399	96%	Yes, native
Fashionopolism	$350	252	–	Yes, native
Icon	$250	369	–	Yes, native
Drop	$250	19	–	Yes, native
Vantage	$150	230	–	Yes, native
Foodie	$180	22	–	Yes, native
Forge	$180	15	–	Yes, native
Mr. Parker	$160	207	–	Yes, native
Pose	Retired	–	–	Yes, legacy

How to set up Rubik on any Underground theme

The process is identical for all 9 themes. Five minutes, no code.

Install Rubik Variant Images from the Shopify App Store.
Go to your Shopify theme editor and enable the Rubik app embed. The app auto-detects your Underground theme.
Open a product in the Rubik dashboard. Drag and drop images onto each variant, or use AI auto-assign to let the AI match images automatically.
Enable swatches. Choose image, color circle, or pill button type. Mix different types per option if you want (images for Color, pills for Size).
Preview the product page. The gallery now filters to show only the images for the selected variant.

If something looks off after setup, check the variant images not showing troubleshooting guide. Most issues come from browser caching or a missing app embed toggle.

For bulk catalogs, use bulk assign to process hundreds of products in the background using Shopify gallery order.

If your colours live as separate products rather than variants of one product, Rubik Combined Listings groups them into a single listing with swatches instead. Free to install, 5.0 stars across 78 reviews.

Pairing with Rubik Combined Listings

Rubik Variant Images handles the product page: filtering images, rendering swatches, keeping the gallery clean. But what about collection pages? What if you want to show color swatches under each product card so customers can see available colors before clicking through?

That is where Rubik Combined Listings comes in. It links separate products together (one per color, for example) and shows swatches on collection pages. Each color gets its own URL for SEO. The two apps work together: RCL for collection page grouping and swatches, Rubik Variant Images for product page image filtering and swatches.

Both apps support all Underground themes. Both use metafield-based loading with no external API calls. And both render inside Shadow DOM, so they stay isolated from Underground’s theme CSS.

If your store has products with many color options and you want the full experience (collection swatches + product page filtering), check the complete variant images guide on Craftshift for the full picture.

“This app works perfectly for linking variant images to product options. Super easy to set up and integrates smoothly with my Shopify theme. It’s saved me so much time and made the shopping experience much clearer for customers. The support team was also quick and helpful.”
Anonymous merchant, 5.0 rating, October 2025, Rubik Variant Images on the Shopify App Store

See the live demo store, watch the setup tutorial, or read the getting started guide.

Try Rubik Variant Images free

Frequently asked questions

Which Shopify app should I use for rubik variant images underground themes?

Rubik Variant Images, built by Craftshift, is the app we build for this. It holds 5.0 stars across 436 reviews and carries the Built for Shopify badge. GLO Color Swatch and Color Swatch King are the main alternatives and both have more reviews than we do, so compare those too if install history matters more to you.

Does Rubik Variant Images work on all Underground themes?

Yes. Rubik has native support for all 9 Underground themes: Testament, Fashionopolism, Icon, Drop, Vantage, Foodie, Forge, Mr. Parker, and Pose. The app auto-detects each theme and applies the correct variant picker selectors.

Do I need to edit any theme code?

No. Rubik uses Shopify’s app embed system. You enable it from the theme editor with one toggle. No Liquid files are modified, and theme updates will not break the integration.

Will Rubik’s swatches conflict with Underground’s theme CSS?

No. Rubik renders swatches inside Shadow DOM, which isolates the swatch CSS from the theme’s styles. You get 100+ CSS variables to customize the look without worrying about conflicts.

What about Pose, which is retired?

Rubik still supports Pose. If your store is running it, variant image filtering and swatches work normally. We keep retired themes in our codebase so existing merchants are not left stranded.

Can I use AI auto-assign on Underground themes?

Yes. AI auto-assign is a per-product feature that analyzes product title, variant names, image filenames, and alt text to match images to variants. It works on any supported theme, including all Underground themes.

How much does Rubik Variant Images cost?

Flat pricing, not tied to your Shopify plan. Free for 1 product, Starter $25/month for 100 products, Advanced $50/month for 1,000, Premium $75/month for unlimited. Every plan includes AI credits.

Does Rubik show swatches on collection pages?

Yes, for a single product’s variants. Since May 2026, Rubik Variant Images shows product card swatches on collection, search, and listing pages, so a shopper can swap a card’s image (and price) right from the grid. That covers one product’s own colors. For collection swatches across SEPARATE products (each color its own product and URL), use Rubik Combined Listings, which links separate products and shows swatches on collection pages. Many stores run both.