That's completely and utterly bonkers. First of all, Russia has nuclear weapons. No one is ever going to invade Moscow as long as that is the case. Full stop.

Second, even if there were no nuclear weapons in play, NATO ain't the USA and UK alone. Most NATO states had more or less castrated their military to the point that even successful conventional defense depends cooperation with all other members. That's over since 2014 and even more so since 2022. Putin woke the sleeping giant. Germany alone will more than match Russia's conventional military in the future. Putin created his own opponent. Before that, NATO was structurally incapable of attacking Russia conventionally without a year long buildup of forces.

And finally, if it comes to the thread of a color revolution: Putin has had all the chances to both develop close and lasting ties to the EU and make his own people happy. He had the money and the tools. All he would have needed to do was to stop running the country like a mafia clan. He could have gone down in history as the great Russian reformer but now he will go down as its grave digger.