How can I return a value to a cell, that counts the number of grey filled
cells
in a particular row ?

ie I have rows of 12 cells, some with only 7 cells I need to count, so I
fill these cells grey.
However some filled cells have no value in them, but I still need to
count these cells for my total.
It's not the value in the cell I need, just whether or not it is
color-filled.

I'm not sure if this can be achieved.

Thanks.