Q223: What's meaning of colors assigned to reservations?

The administrator/moderators can assign of of the available colors to each reservation. There is no special meaning of this from the system's perspective but you can give the colors the meaning understood by the moderators, e.g. red could mean some reservation details are still missing and must be sent by the customer etc.

In Site Settings / Color labels (click here to access this page) you can add labels to the colors so that all moderators will be able to hover over the color square to see the meaning.