As per the source, the new Mi Band 4 will indeed sport new colour OLED display for the very first time after monochrome display on the predecessor. It will come with more attractive and colourful UI. This time the new Mi Band 4 will come packed with larger 15 mAh battery to last longer as it sports colour display.
Mi Band 4 will also get support for Bluetooth 5.0 for the first time. The Mi Band 4 will come in two variant one with NFC with model number XMSH08HM and without NFC the model number XMSH07HM. It will come with an improved Heart Rate Monitoring system.
The new NFC variant of Mi Band 4 will cost 499 Yuan (Rs.5024/-) and non-NFC at 200-300 Yuan (Rs.3000/-) in China.