Vehicle class names:
I_APC_Wheeled_03_cannon_F
I_UGV_01_F
I_UGV_01_rcws_F

Code for APC_Wheeled:
class CfgVehicles {
class I_APC_Wheeled_03_base_F;
class I_APC_Wheeled_03_cannon_F : I_APC_Wheeled_03_base_F {

		hiddenSelections[] = {"camo1", "camo2", "camo3", "camo4"};
		hiddenSelectionsTextures[] = {"test\data\APC_Wheeled_03_Ext_INDP_CO.paa", "test\data\APC_Wheeled_03_Ext2_INDP_CO.paa", "test\data\RCWS30_INDP_CO.paa", "test\data\APC_Wheeled_03_Ext_alpha_INDP_CO.paa"};

};
};

I've used all the base classes and checked the RPT for errors which shows none. It will sometimes overwrite the modified class with another base class but even replacing them will show the same result with no use of modified hiddenselectiontexture.