Fast, accessible redesign for Aquarium Co-Op: +18% conversion rate
Test run byBlend CommerceCRO agency
Commentary byLiftArchiveOur analysis, not theirsAquarium Co-Op rebuilt its Shopify store on a fast custom theme with a simpler layout and a more readable yellow-and-black palette, and conversion rate rose 18% quarter on quarter.
Blend Commerce ran the redesign as part of a long-running growth partnership.
This is a before/after comparison, not a split test.
- Conversion rate: +18%, comparing Q1 2021 with Q4 2020.
- Store revenue: +144% over the same quarters. Most of this likely came from more traffic, not the redesign alone.
- Store sessions: +73%. Traffic rose sharply in the same period, so the revenue number mixes design and traffic effects.
- No split test was run, so none of these changes can be credited to speed or colour on their own.
The change
Same store, rebuilt on a faster theme with a higher-contrast yellow and black palette
Simplified mockup drawn by LiftArchive from the shared screenshots.
Control
The old store ran on a heavily customised Shopify theme (Turbo by Out of the Sandbox). The brand's main colour was green, and the agency felt it could not make that theme any faster.
Variant
A new custom theme built from Shopify's Debut theme, with speed as the core goal and a simpler layout. The primary colour moved from green to yellow with black text so more people could read it easily.
Why it likely won
Our reading of the result, not the practitioner's claim.
- A faster site lowers the chance that shoppers give up while pages load, especially on mobile.
- Black text on yellow gives stronger contrast than the old green, which can make prices and buttons easier to read.
- A simpler layout can cut the effort needed to find and buy a product.
- Q1 often brings new hobbyists after the holidays, so some of the lift may be seasonal (our guess, not stated by the source).
Caveats: This compares one quarter with the one before; it is not a split test. Sessions rose 73% in the same period, and seasonality and traffic mix were not controlled.
Who ran it
Blend Commerce ran this test for Aquarium Co-Op and published the results (Blend Commerce case study). The numbers are theirs; the summary and commentary on this page are ours.
Read the original case study on Blend Commerce →
How to run this test on your store
- Hypothesis
- If we move to a faster theme and raise text contrast on key elements, then more visitors will complete a purchase because pages load sooner and are easier to read.
- Primary metric
- Conversion rate (orders per session)
- Guardrails
- Average order value
- Bounce rate on mobile
- Page load time (Core Web Vitals)
- Who should test it
- Stores on a heavy or slow theme with lots of mobile traffic. If your site is already fast and readable, expect a small effect, and a full redesign is hard to split test, so consider testing contrast and layout changes one at a time.
Questions
Does site speed affect ecommerce conversion rate?
Often, yes. Slow pages give shoppers more chances to leave, though the gain is smaller once a site is already fast.
Can you A/B test a full site redesign?
It is possible but hard, because two full themes must run side by side.
Many stores compare before and after instead, which cannot separate the design from traffic or seasonal changes.
Does colour contrast matter for conversions?
Better contrast makes text and buttons easier to read for everyone, including people with low vision.
Its effect on sales is rarely measured on its own.
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