There is only 1 global firmware for X3, but at least 3 new Chinese firmwares have already been released, but this global one is already outdated, the latest Chinese firmware is April / May v3.1.2.2, but it can no longer change the language to English.
For me, the optimal firmware is 2.6.1.1, it is the penultimate one, that is, not old, you can change it to English and there are all color and image settings in the android hidden menu.
I know Chinese firmware.
1.9.xx
2.1.9.8
2.5.xx
2.6.1.1
3.1.2.2 - last April/May. 2.1.9.8 is no longer a new firmware.