I second the demand, even if camouflage is not taken in consideration by the Visibility System yet.
But have it optional, as a checkbox or a toggle button, so that you can have different camouflage if you want so.
Next to the camouflage menu (see screenshot), add a checkbox with a "Same for all" label.
Then, somewhere in the equipment function, add, for example, just before changing soldier and/or before exiting to aircraft screen :
(soldier "k" being the current soldier)
if (camoForAllchecked == TRUE) { for (j++) {soldier[j].camo := soldier[k].camo};}
If the others soldiers are out of range, make the camoForAllchecked a more global variable, and add the line just after returning from the equipment function.
Alternatively, add another property to the object "soldier", then :
if (soldier[k].camoForAllchecked == TRUE) { for (j++) {soldier[j].camo := soldier[k].camo}; soldier[j].camoForAllchecked := TRUE;}
... that's the idea.