* Under the moon gives an evil little laugh.
I am not a GM, but I have written a few events. Any who found themselves in a few of them found out that you don't always get rewards. The events were their own reward.
On the subject of the Yellow labels, sometimes they are needed, sometimes not. Let's look att he pros and cons.
Pros: People know an official event is going on, and not a player. Does that make a difference? Yes. Player events are not necessarily inside of the settings. I, myself, am quite wary about joining player events. I have been dragged into a few that I did not enjoy by the end because they went so off the wall.
Notice. More people will notice a Yellow, and take heed. The events I helped run sometimes got ignored until the Yellow label was turned on.
Behavior. Players behave themselves better if they see the Yellow. Some of them, anyways. There is less of a chance of folks trying to godmode the situation with their 'unique' character powers.
Cons: Notice. Sometimes too many people notice the Yellow, and the event becomes a mob. The events I designed got around this by either making it so that it was actually intended to for this mob, or by being selective in who was chosen to be in the event to keep the numbers down and in character.
OOC. Yes, folks will go out of character to be in an event. Good guys might do bad things, bad might do good. Folks will do things they normally will not. That is not the GM's fault.
Reward. Everyone expects a reward at the end of a GM event. I guess that would be the reason for the first two cons. My advice is not to give rewards every time.
Several alternatives have been tried. Announcing an event and type of characters wanted on the forum worked very well, even though some people wined that it was OOC. Silly people. Another thing that worked was 'whispering' in folks ears ingame, selecting just the right amount of people. I did this by looking at character descriptions to select the 'right kind' as well. Blue NPC labels actually work quite well as well. They do get some notice, but not a great deal. Going around with a Green and asking folks to help or join you fails terribly.
The hardest part of making an event is to design it so that only certain character types will join in. They are like quests to some folks who do every quest not because it is something their character would do, but because they want to do them all. You also have to design them so that people who did not join don't feel left out. It is a hard balance to keep. Thing about that the next time someone shouts out "This is why I don't do GM events!" What did that moron who shouted that really achieve? Nothing positive.