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.