I haven't made up my mind, entirely.
First, I'd be the first to state that Putin's default hat is black. In this case, I'd say that by going beyond repulsing the Georgian attack, and by occupying Georgian territory beyond Ossetia, the Russians earned a black-ish hat. (Destroying Georgia's ability to repeat its aggression was illegal, I suspect, albeit entirely understandable). If the Russians are back within South Ossetia and a 14-km buffer within ten days, that black hat fades, somewhat.
On the other hand Georgia attacked a national entity from which its armed forces were specifically excluded by an internationally validated ceasefire agreement (that's black hat behaviour) and attacked Russian peacekeepers (and so's that). That territory is presented as 'part of Georgian sovereign territory' but its population have overwhelmingly voted for full independence, and even Georgia has recognised Ossetia's 'special case' status by offering 'autonomy'. With that in mind, it's not just a matter of Georgian internal affairs.
I see no compelling evidence to support the contention that Russia used this as an excuse to launch a long-planned aggression. Firstly, it looked reactive and far-from-well-planned, and secondly, they seem to be withdrawing when they could plainly have swept on to Tbilisi had that been their aim.
So this does not show Russia's 'true colours'. Indeed Russia's military action (if they do move back to their pre-war positions within a reasonable period) will be (or will appear to be) more justified and more proportionate than our own invasion of Iran.
However, Putin's Russia does deserve a black hat for plenty of other reasons, and it has shown its true colours by threatening to nuke Poland.
So by all means criticise Russia, but do so for the right reasons. I'd suggest that its actions in South Ossetia are not the right reason, and look like unjustified Russki-bashing, undermining the very real case that could be made against them.