If you built a UDF that examines this property, then you can add a dummy
column next to your data with this function and filter on the results of
this function.
Assume data is in A2:C25 and you want to filter on a background color of Red
(not produced by conditional formatting) for column A.
Put the below function in a general module (insert=>Module in the vbe), not
a sheet or the thisworkbook module.
Public function ShowColor(rng as Range)
ShowColor = rng.Interior.ColorIndex
End Sub
In D2 put in the formula
=Showcolor(A2)
then drag fill down to D25
in D1 put in the header Color
then apply the autofilter and filter on the value 3. (colorindex for red is
3).