Auxilium appears not to be working for camoflague. Two issues:
preset styles - this is mentioned in the mod kit preview. It will not show preset styles that have been selected and applied once you select another tank in the garage. If you click on exterior, then the preset style will appear in the customization hangar and you cannot select apply - returning to the garage will show the preset style applied, until you select another tank - then if you return to the first selected tank, it will not remain applied but it appears to be applied in battle, as the note from Auxilium states.
custom styles - I cannot get custom styles to remain applied in the garage. I apply a custom style, then select another tank in the garage. If I return to the first tank the selected custom style has been totally cleared. Unlike for preset styles, going to the customzation hangar does not show the style that was previously applied - the tank is totally clean and you would have to start again. Nor is the custom style appearing in battle for a tank that did not show it applied in the hangar.