According to the Verge, users on Reddit, Twitter and other social media channels reported the problem just days after Apple Watch was launched. According to tests conducted by iMore, the Apple Watch can run into significant problems if worn by inked customers.

The tests produced misleading heart rate measurements on solid black and red colours. Tattoos with lighter colors seemed to give Apple Watch less trouble, only leading to heart rate readings that were slightly off the mark.

Apple wants outlets to promote Watch as fashion item

The Apple Watch launched quietly around the world on Friday without the usual frenzy or fanfare for an Apple Inc rollout, as a handful of boutiques in major cities like Tokyo and Paris sold the timepiece - but not for purchase at its own stores.

Shops included The Corner in Berlin, Colette in Paris, Maxfield in Los Angeles and Dover Street Market in Tokyo and London. Apple courted the outlets to promote the watch as a fashion item rather than just another techie gizmo.
The watch has been on display in Apple stores since April 10, when it became available for preorder. Customers began receiving the smartwatch on Friday, though there were delays to June or later as Chief Executive Officer Tim Cook's first product has drawn more demand than expected.
Paired with an iPhone, the watch allows users to check email, listen to music and make phone calls. It also tracks a person's health, for instance by monitoring heartbeats or tracking calories burned during a workout.
Several customers said they planned to buy the watch online after trying it, while others had already preordered it but had yet to see it in person.
Reviewers say the smartwatch could make life easier for people on the move, but gave it poor marks for battery life and slow-loading apps.
Technology lovers and investors keen to find out the watch's components were frustrated, with a tough resin coating protecting the core computing module from immediate scrutiny.
Gadget repair firm iFixit, which has successfully pried open other Apple products on their launch day, said the U.S. Company also appeared to be promoting the watch's inner workings, complicating a detailed analysis of its origins from underlying parts suppliers.