A wrist device comprising: a curved body arranged to fit the wrist device around a user's wrist; an activity tracker circuitry configured to measure physical activity of the user of the wrist device; a processing circuitry configured to acquire physical activity-related measurement data from the activity tracker circuitry and to process the physical activity-related measurement data into physical activity-related metric characterizing the physical activity of the user; and a user interface element configured to display the physical activity-related metric, wherein the user interface element comprises: a light emitting diode matrix layer comprising a plurality of light emitting diodes arranged in a matrix form, characterised in that the wrist device further comprises a fluorescent layer configured to alter the wavelength of the light emitted by the light emitting diode matrix layer, wherein the light emitting diode matrix layer comprises: a first layer electrically coupled to an electrical terminal, a second layer comprising the plurality of light emitting diodes , wherein the plurality of light emitting diodes are electrically coupled with the first layer , and a third layer electrically coupled with the plurality of light emitting diodes , wherein the second layer comprises electrical lead-troughs electrically coupling the first layer and the third layer , and wherein at least one of the first layer , the second layer , and the third layer is manufactured by utilizing electronics printing technique. a curved body arranged to fit the wrist device around a user's wrist; an activity tracker circuitry configured to measure physical activity of the user of the wrist device; a processing circuitry configured to acquire physical activity-related measurement data from the activity tracker circuitry and to process the physical activity-related measurement data into physical activity-related metric characterizing the physical activity of the user; and a user interface element configured to display the physical activity-related metric, wherein the user interface element comprises: a light emitting diode matrix layer comprising a plurality of light emitting diodes arranged in a matrix form, characterised in that the wrist device further comprises a fluorescent layer configured to alter the wavelength of the light emitted by the light emitting diode matrix layer, wherein the light emitting diode matrix layer comprises: a first layer electrically coupled to an electrical terminal, a second layer comprising the plurality of light emitting diodes , wherein the plurality of light emitting diodes are electrically coupled with the first layer , and a third layer electrically coupled with the plurality of light emitting diodes , wherein the second layer comprises electrical lead-troughs electrically coupling the first layer and the third layer , and wherein at least one of the first layer , the second layer , and the third layer is manufactured by utilizing electronics printing technique. a light emitting diode matrix layer comprising a plurality of light emitting diodes arranged in a matrix form, characterised in that the wrist device further comprises a fluorescent layer configured to alter the wavelength of the light emitted by the light emitting diode matrix layer, wherein the light emitting diode matrix layer comprises: a first layer electrically coupled to an electrical terminal, a second layer comprising the plurality of light emitting diodes , wherein the plurality of light emitting diodes are electrically coupled with the first layer , and a third layer electrically coupled with the plurality of light emitting diodes , wherein the second layer comprises electrical lead-troughs electrically coupling the first layer and the third layer , and wherein at least one of the first layer , the second layer , and the third layer is manufactured by utilizing electronics printing technique. <EOS>