Diet Coke answered falling sales with slimmer cans and a colour stripe per flavour

Diet Coke was losing ground in a pressured low-and-no-calorie category, and the brand needed to appeal to a wider audience without discarding the core visual assets people recognise.

Slimmer, taller cans stripped of imagery, with a vertical coloured stripe marking each of five flavours — Diet Coke's answer to Coke's red disc

The Coca-Cola Company's in-house design team under VP of design James Sommerville, with studio Kenyon Weston, refined the typeface flatter and bolder, simplified the palette to silver and red, and added a vertical coloured stripe per flavour — original, ginger lime, feisty cherry, zesty blood orange and twisted mango — informed by research with 10,000 US consumers. The design rolled out across the US in January 2018 and Canada in February, with a US ad campaign to follow.

No post-relaunch sales results are given in the source; the redesign shipped as the platform for five new flavours, with the stripe positioned as Diet Coke's equivalent of the original Coke's red disc.

In January 2018 Diet Coke rolled out a major packaging overhaul: slimmer, taller cans stripped of all background imagery apart from a flat graphic fruit symbol per flavour, a flatter and bolder wordmark, a simplified silver-and-red palette, and a vertical coloured stripe distinguishing five flavours — original, ginger lime, feisty cherry, zesty blood orange and twisted mango. The relaunch came as the drink's sales slipped.

The work was led in-house by The Coca-Cola Company's vice president of design James Sommerville alongside studio Kenyon Weston, and rested on research with 10,000 US consumers into the flavours, visual identity and can design. Sommerville described the stripe as the equivalent of the red disc on Coca-Cola Original packaging, standing for drinkers 'continually on the move, with confidence'.

The context was a pressured category: UK off-trade sales of Diet Coke fell 0.6% to £420.2 million in 2017, according to Marketing Week, while in the US Coca-Cola Zero Sugar's sales grew 52% after its launch the year before. The new design rolled out across the US in January 2018 and Canada in February, with a US advertising campaign launching the next month; a UK or worldwide rollout was unconfirmed.

It is a case study in evolving a masterbrand's assets instead of resetting them — the typeface, palette and disc logic all trace back to Coca-Cola's system.

Packaging carries the whole launch: the stripe differentiates five flavours on shelf without photography or illustration.

Large-scale consumer research — 10,000 US consumers — drove both the flavour lineup and the visual identity, not just taste tests.

A redesign that survives is an amplification of assets people already recognise, not a reinvention — the stripe earns its place by doing a job the red disc does for Coke.

The source, published 11 January 2018, ends at the rollout plan: US first, Canada in February, a US ad campaign the following month, and no confirmation on a UK or worldwide release. No sales or awareness results for the redesign appear.