an act of utter stupidity to single out their homes in this way

But did they?
It was a letting company that had always used the same colour paint.
They were asked to house some asylum seekers and it just never occurred to anyone that there might be an issue with the normal pracatice.
As soon as there was it was dealt with.

Wristbands are a very common way of identifying which people are entitled to which perks.
You wear them in 5* all inclusive hotels!
It would not help anyone if all the food disappeared before those actually entitled to it arrived.

Again, it just never occurred to anyone that it might be an issue, and as soon as it was it was rectified. Cards instead of bands.

It is extreme paranoia to imagine a government conspiracy in any of this.