vtable: row colors based on their object values

[ijqq]

Hello,

I am trying to write a simple interface using the vtable package. I would like 
the background colour of each row to depend on the value of its underlying 
object (e.g., the row should have a green background if thefoo​ field of the 
object it represents is 1, otherwise it should have a plain white background). 
I am a beginner in Emacs List and am wondering what the best way to do this is.

The :displayer parameter to the vtable​ takes the formatted string of the text 
only so it wouldn't affect the background for the whole row. The :row-colors 
parameter takes a list and not a function, so I'm a bit stuck on updating it 
properly. I tried to set :row-colors to be the value of a global variable which 
is set by my :objects-function function, but now when updating the table, the 
colours become out of sync.

What is the best general approach?

Thank you