So I've just entered the part labeled "Agony," and there's a couple questions that are bugging me:

1) What does it mean when a Sisters' chamber has a glowing, pulsing aura around it? It's been around that girl with the blue tattoo on her face the entire game, and occasionally I notice it elsewhere.

2) What does silver do when in your hearts? I've had no events that seemed random.

3) I killed all of the brothers as soon as they appeared in the last phase, leaving only Montgolfier. Is there a way to attack him? I kind of get the feeling my gamer perfectionism has gotten the best of me, as it seems strange that they've only now gained the ability to attack sisters, after the brothers are almost all dead.

4) Attacking with the color highlighted on the outermost remaining ring during the boss fights did more damage, right? Sometimes I couldn't tell if I was imagining it.

I wish there were a way to add color to your hearts before encountering the wandering sisters. It's annoying losing a little precious gold because I have to add it before meeting one on the world map, especially since I'm trying to max out the creepy feral chick.

2- Silver allows you to do less damage to a realm when using colour in it.

3- You'll fight him soon enough

4- You are correct, using the colour currently highlight in the brothers ring gives double damage.

You can always pay attention to your path, most of the time you can predict when you'll encounter Aya and Echo.

It usually means she wants to talk to you.
Use of colour in chambers slowly destroys the whole group of chambers around the sister. Use of Silver lets you deal less damage to the world (isn't it written in the game's journal?). Better to say, if you have 100% "silver" characteristic ('Cold'), then you deal two times less damage. You may make it even smaller using Red for violent acts, Gold for SIsters or Violet for trees. This way you reach the same effect while technically using less colour. For example, if you choose to release Ole, then you can save 65% of her chamber's health by using 100% gold and silver. However, her realm ends up almost dead if you do this without any Gold or Silver.
Twice as much, to be more exact. We even included this info in the game's manual, given that there is hardly any info about that in the game (which is surprising to me; though, how are we supposed to explain this without NPC's talking explicitly about the interface?).

The quote from the in-game journal is, "The more silver you have inside of you, the better chance you will have in random events." Which makes no sense at all. Based on that information, I'd been loading silver into me while in the void (hoping for some random events), then dumping it when I entered a chamber. Now I've done everything as painstakingly perfect as I can manage for hours and hours of playtime, and yet it turns out my game world is irrevocably damaged because of a bad journal entry. I guess I can always cheat, but after all this work, that strikes a very disagreeable note.

Oh, really... This is a complete nonsense, as there don't seem to be any random events in the game. Actually, what Ava says about Silver is a bit obscure, but generally close to the truth. Silver reduces the damage you do to the realm when painting in the Chambers. It doesn't matter in fights with brothers (their arenas are not in any particular area of the Void)

What about appearance of the colours at the beginning of each cycle? It seems to be quite random event, though I'm not sure how does silver help it to happen. locate colours closer to player position? increase overall amount maybe? force brothers to smoke in theirs chambers rather than invade sisters or gardens, at least? If these are ever allowed by the game mechanichs at all. I'm void of better ideas:)

Also, what exactly is meant by this destructive usage of colour in the chambers around the one of a sister?, aside from predators activity which seems to increase with every drop regardless what chamber i misfortuned to visit.

The income from the trees in directly proportional to the amount of domain health left (i.e. trees in 50% damaged area give two times less lympha). After a certain level of damage nasty monsters start appearing.

Ok, understood. Will come in handy next time i get my hands on the Void.

Was the thing about realm damaging and Silver preventing it true also for the Tension/Turgor version? Here you mentioned that the "realm destruction" thing was a new thing introduced in the The Void version - if so, what was the role of Silver previously? From what I remember, both the manual and the game journal mentioned it being responsible for player's "luck", but I think there was generally not much Silver appearing both times I played (the version I own is the Polish Tension one), and I don't remember seeing any major influence on the game with what Silver I had my hearts then...

What I said is true only for the new release. In the original game use of colour hardly affected anything in the world. It slightly modified some numbers if large percentage of a certain colour had been used, but I think this modifiers were small enough, so that the changes wouldn't be noticeable. The_LxR can probably tell more about the system in the 2008 release.