If I enter the colour menus I see that the grid has moved to the far right (pink/red) side.
By default, the X-T2 has White Balance assigned to the right selector button. Pressing the selector right once brings up the white balance menu. If you're already in auto white balance then another press of the right selector button takes you to the WB Shift screen. More presses to the right will push the white balance shift towards the red end.
It seems entirely reasonable that unknowingly/accidentally pressing right several times would cause the white balance to shift. Only pressing the BACK button or turning the camera off will cancel the accidental white balance shift, but pressing your shutter release is the same as pressing OK, so that would accidentally lock in the WB shift changes =(
I personally don't change white balance that much and removed white balance from the right selector button. If you need quick access to white balance, I would suggest assigning it to function button 1 (between shutter speed dial and exposure comp dial) or to the My Menu.