You might want to change the background color. Here is an example I did that has three background colors.
This needs to go in the grid refresh

this.SetAll("DynamicBackColor", ;
   "IIF(ann.typ = 'WO', RGB(180,255,220), ;
   IIF(ann.typ = 'WR', RGB(255,220,180), ;
   IIF(ann.typ = 'PM', RGB(220,255,255), RGB(255,255,255)) ))", "Column")  

In this code, ann.typ is a cursor field and "WO" is the data.
You could just as easily use a time.

HTH