Longtime customers of Target’s pharmacies are finding a change in pill bottle design hard to swallow.

After CVS began operating Target’s drugstores earlier this year, distraught customers have been asking — in some cases begging — the chain to bring back the retailer’s red prescription bottles, which came with color-coded rings, labeling on the top and prescription information that was easier to read.

CVS says it is working on designing a new system for dispensing prescriptions and helping people stay on their medications, but a spokesman gave no details. Meanwhile, shoppers continue to mourn the loss of a bottle that was considered groundbreaking when it debuted about a decade ago and was once on display at New York’s Museum of Modern Art.

Target flipped bottle design on its head in 2005 when it introduced a red container with the opening on the bottom. That allowed the label to wrap around the top so it could be seen from above. It included a flat surface that customers found easier to read than the curve of a typical pill bottle, and it came with color-coded rings to help people tell their medicines apart.