When you are on RSVP's FOH tool (where you manage your guest bookings), you will have a few colors to decode when viewing your table layout. Below is a sample view and the corresponding colors.
Dark grey - available and bookable. Click on one to create a booking assigned to that table. Or, click on the green "+" button in the bottom righthand corner to create both a booking with an assigned or unassigned table.
Light grey - the table is booked at the seating time selected. Click on the table to view a summary of the upcoming booking.
Green - the booking on that table has arrived. The guest's name is moved out of Upcoming to Seated tab when you seat the table (Hint: click on the booking then Seat Table to seat the guests). A timer starts counting once the guest is seated so you know how long your guests have been there. Walk-ins are always automatically seated, so you will only find them in your Seated or All tabs.
Stone grey - the table is currently available, but there is a booking on that same table within the time you allow guests to have in the rules. This helps your staff know not to accidentally book a table that will be occupied in the near future. It also means you can allow a guest walking in, for example, to dine with the understanding that they have less time than usual.
Note: In RSVP's new FOH, combined tables no longer show as a larger table overlaying two smaller ones. This means you can now combine multiple tables from the FOH and even combine ones that are next to each other. Combined tables will now show as individually numbered in the Bookings Panel (e.g. Ian Knight on 18 & 19). If you click into a booking with multiple tables, they will be highlighted with a white border visually.