When you use Object Spy to identify your grid, do you have a property called "wValue" or something like that as part of the grid? It probably has a button called "Params" next to it. So you might be able to use something like:
myGrid.wValue(2,0)
That might get you access the cell itself, but then we still need to verify what you actually need to verify. I can't find a "color" property in the grids I use, but I'm wondering if there are any other differences between the 'phone' icons you need to differentiate between. If there is a difference in size (my 'read' icon is 20 pixels wide, but my 'unread' is only 15), you could use
if(myGrid.wValue(2,0).Width==15) //do something
But once you can look into the cell values, you might be able to find some other differences that, while not technically telling you if the color of your image is black, might still tell you what you need to know. For example, if you're REALLY lucky, the devs might have used the "Tag" property to differentiate between different phone statuses or types or whatever.