# Colour electronic shelf labels: three colours, four or six

> Refresh time, battery life and cost of colour electronic shelf labels by panel type, and when colour pays for itself. Dated sources.

Source: https://etiquetaselectronicas.io/en/technology/colour-electronic-shelf-labels/
Published: 2026-11-09 | Updated: 2026-11-09

A colour electronic shelf label only pays off when the colour changes a buying decision or prevents a mistake, and almost never when it merely makes the label look nicer. Three-colour (black, white, red) and four-colour (adding yellow) panels cost little more than black and white; six-colour panels multiply price, refresh time and energy use.

Below we compare the three tiers using the public figures we could check as of 9 November 2026. For how a whole installation fits together, see [electronic shelf label technology](https://etiquetaselectronicas.io/en/technology/).

## What the acronyms stand for

**BWR** is black, white and red. E Ink describes its Spectra 3000 family as a three-colour display for shelf labels, with black, white and red or yellow particles. **BWRY** is the four-colour variant: the same idea with yellow added. You can draw a struck-through price in red and a yellow "sale" background, but not a gradient or a photo.

**Six colours** is a different thing. E Ink's Spectra 6 combines white, red, yellow and blue particles to produce six base colours, according to Waveshare's page for its 7.3-inch module. It looks more like a printed poster than a price tag, which explains every other number on this page. E Ink's Spectra 6 page gives an operating range of 0 to 50 °C.

## Refresh time

Between one type and the next there is a step, not a slope.

| Panel | Public figure | Source |
|---|---|---|
| Black, white, red, 2.9" | 15 s full refresh | Waveshare |
| BWRY (typical label) | 4-7 s | Retail Digitals (2026) |
| Six colours, 7.3" | 25 s | Waveshare |
| Six colours (commercial label) | 18-25 s | Retail Digitals (2026) |

The figures do not line up perfectly, and that is normal: they depend on size, temperature and the waveform each maker uses, and the Waveshare pages describe development modules, not store labels. In [LCD versus e-paper](https://etiquetaselectronicas.io/en/technology/lcd-vs-e-paper/) we cite another source that gave 12-15 s for colour in general; a workable range for six colours is roughly 12 to 25 s, and E Ink does not publish the figure on its product page.

Does it matter? For a price change at night, no: the platform does it in the background. It matters in two situations. One is changing prices while the store is open and a shopper is looking at the label; Retail Digitals notes that the colour animation during a long refresh "is noticeable", while on BWRY it goes unnoticed. The other is launching a promotion at an exact time across thousands of labels, because 25 s per label adds up depending on how many update in parallel. Plan the window; do not trust the first second.

## Battery

Colour costs energy every time the image changes. Standby and static-image consumption remain close to zero, as with any e-paper (see [battery life of electronic shelf labels](https://etiquetaselectronicas.io/en/technology/electronic-shelf-label-battery-life/)).

Retail Digitals, the US distributor of ZKong labels, publishes a guide by its sales director that estimates that a six-colour refresh uses about 2.4 times the energy of a BWRY one, and from that derives a battery life of 4 to 6 years with one change a day, against 8 to 10 years for BWRY. It is the only comparative estimate we found and it is not an independent measurement, so treat it as an order of magnitude. What does hold up logically: the more often you change the image, the more the gap narrows in favour of the simpler panel, and every battery swap on a shelf is a labour cost.

## What colour costs

The same guide gives a 2026 reference price of 14 to 18 US dollars for a 4.2-inch six-colour Hanshow label, against 5 to 7 dollars for a BWRY label of the same size. These are US prices from one source, not European list prices or volume quotes, so do not use them as a budget. They do show the proportion: two to three times more per label.

There is a less visible cost: template design. The guide puts it at 40 to 80 dollars per six-colour template against 15 to 30 for BWRY. With three promotion formats it hardly matters; with thirty, it does.

The author reports, across fourteen budgeted projects, that full colour pays off for only about 9 % of the SKUs in a typical store, and that the usual answer is to combine it with BWRY elsewhere. That is an experienced opinion, not a market statistic. With that 9 % and your own catalogue you can run the numbers in the [total cost calculator](https://etiquetaselectronicas.io/en/tools/esl-tco-calculator/).

## When colour pays and when it does not

**When it pays**

- *Promotions and markdowns.* Red is enough here, and BWR covers it. A struck-through price with the new one in red reads from a distance and needs nothing more. This is the main, cheap use.
- *Making what you advertise match what you charge.* If the reduced price is a real offer, it should match what the till charges; [a till price that differs from the shelf price](https://etiquetaselectronicas.io/en/regulation/shelf-price-different-from-till-price/) explains why that is a legal problem and not only an image one.
- *Long-decision products.* The Retail Digitals guide cites cosmetics, premium wine and spirits, and electronics, where the shopper spends minutes at the shelf and the image is part of the sale. It mentions a beauty-chain pilot with +14 % aisle conversion, reported by the same author without independent verification. Treat it as a hypothesis to test, not a result. For your case, see how the [consumer electronics sector](https://etiquetaselectronicas.io/en/sectors/consumer-electronics/) approaches it.

**When it does not**

- Supermarkets, drugstores, DIY and pharmacy: the shopper spends 30 to 90 seconds at the shelf, according to the same source, and wants a price. BWRY covers everything reasonable.
- Anywhere labels refresh many times a day.
- If the reason is "it should look modern". Six-colour e-paper does not match an emissive screen: Retail Digitals compares it to CMYK print at "around 80 % of the saturation" of a glossy photo.

## The allergen question

This is the use people ask about most and the one that needs most care. For food sold loose, Regulation (EU) No 1169/2011 requires allergen information to be available for non-prepacked food, and leaves it to each member state to decide how it is presented. Germany, for instance, requires it to be clearly visible, distinct and easy to read, and available before the purchase is completed. The United Kingdom has its own rules, set out in Food Standards Agency guidance; check them if you sell there.

A practical consequence follows. A background colour that distinguishes "contains gluten" or "lactose-free" may help shoppers find it, but it does not comply on its own: the notice has to name the allergen in words, and someone who cannot tell red from green will not see the warning. Besides, three or four colours cannot distinguish each of the fourteen groups on the official list. If your interest is catering and buffets, where this weighs most, the [hospitality and buffets](https://etiquetaselectronicas.io/en/sectors/hospitality-buffets/) page covers it with the concrete workflow. This page is not legal advice: before relying on a label to convey allergen information, check with your local food authority or adviser.

## How to decide without getting it wrong

1. **Start with BWR or BWRY** across the store. For prices and promotions, which is almost everything a shelf label shows, nothing more is needed.
2. **Identify the few zones where colour is the product** and ask your supplier for a six-colour trial in that zone only, on the same shelf and under real lighting.
3. **Measure the refresh time** of your panel, at your store's temperature, rather than the datasheet figure.
4. **Calculate battery life with your changes per day**, not the assumption of one a day.
5. **Compare the cost of both configurations** at your volume, not with another country's list prices.

## Limits of this page

Most cost and battery figures come from a single guide by a US electronic shelf label distributor (published 15 April 2026), whose data is not verified in the text itself. The seller has a stake in the answer, although here the guide argues against colour for most of the store. The refresh times come from development-module datasheets and that guide. E Ink does not publish the Spectra 6 refresh time on its product page. We found no independent test measuring BWR, BWRY and six colours on commercial labels with the same method. Prices are in US dollars as published and are not converted. If you have a measurement or datasheet that contradicts any figure, we will review and date it.

## Frequently asked questions

### What do BWR and BWRY mean on an electronic shelf label?

They spell out the display colours. BWR is black, white and red; BWRY adds yellow. Both are low-colour e-paper, meant to make promotions stand out, not to reproduce photographs.

### How long does a colour label take to refresh?

It depends on panel and size. A 2.9-inch black-white-red module lists a 15 s full refresh and a 7.3-inch six-colour module 25 s. A US label distributor's guide puts BWRY at 4 to 7 s and six-colour labels at 18 to 25 s.

### Do colour labels drain the battery faster?

Yes, because each image change uses more energy. A guide published by a US label distributor estimates a six-colour refresh at 2.4 times the energy of a BWRY one, and battery life at 4 to 6 years against 8 to 10 with one change a day. They come from a label distributor's sales director, not an independent test.

### How much more do six-colour labels cost?

A 2026 guide quotes 14 to 18 US dollars for a 4.2-inch six-colour label against 5 to 7 for BWRY, so two to three times more. That is a US reference price, not a quote; in your project, volume decides.

### Can I flag allergens with colour alone?

That is not a good idea. For food sold loose, EU rules require allergen information to be clearly visible and legible, in words. Colour can reinforce the warning but should never be its only carrier.

## Sources

- [Retail Digitals, Spectra 6 (Six-Color) ESLs: When the Premium is Actually Worth It (15 Apr 2026, updated 5 May 2026)](https://retaildigitals.com/spectra-6-color-esl-when-it-makes-sense/)
- [Waveshare, 7.3inch E Ink Spectra 6 (E6) Full Color E-Paper (product page)](https://www.waveshare.com/7.3inch-e-paper-hat-e.htm)
- [Waveshare, 2.9inch E-Paper Module (B), red-black-white (product page)](https://www.waveshare.com/2.9inch-e-paper-module-b.htm)
- [E Ink, Spectra 3000 (three colours for ESL)](https://www.eink.com/brand/detail/Spectra3000)
- [E Ink, Spectra 6](https://www.eink.com/brand/detail/Spectra6)
- [EUR-Lex, Regulation (EU) No 1169/2011 on food information to consumers (Article 44, non-prepacked food)](https://eur-lex.europa.eu/eli/reg/2011/1169/oj)
- [Food Standards Agency, Allergen guidance for food businesses (UK)](https://www.gov.uk/government/publications/allergen-guidance-for-food-businesses)