If you like to change the colors for your marked cells please navigate to Setup - Development - Custom Setting. Open the public Custom Setting "ADvendio Settings" by clicking on Manage.
These are named PositionChartCountCellColor with a Number. Enter the color in Hexadecimal format, e. g. #FF9E9E
|2||booked & offered (enough available)|
|3||booked & offered (not enough available)|