The HDMI interface has evolved over the years, with new versions (HDMI 2.2 is the latest) bringing support for new audio and video technologies such as 3D, 4K, 8K, HDR and 4K/120Hz, to name but a few.

If you have a multiple monitor setup & identical monitors are showing different color variations, then you need to carry out Color Calibration & check a few other things.