According to documentation, there are 84 LEDs inside this lantern, likely using various color temperatures, which is what allows you to select different color temp. Not sure how you could replace them all with a single Nichia LED and still maintain uniform light output in all directions.
I thought there are only leds with two colour temperatures, ~6500K (just a guess) and ~2500K. By changing the output ratio of the two type of leds you can get all colour temperatures in between. I haven’t read anything about this, but this is just how it is in my head.