background based on my data

How the set the background of the cells based on myData?
Tried this but doesn't work
obj.defineCellProperty("background-color", function(col,row){

var value = (myData);
var color = "";
if (value > 1) {color = "red" ;}

return color;
});
obj.getCellTemplate().setStyle("background-color", function(){return this.getControlProperty("background-color"); });

Important: I do not want to fill the cells with the data. I only want to show a different background color based on the data in myData.

Thanks in advance. Mark