I have setup a User Defined function that returns the interior colorindex value. Just add this code to a module on your worksheet and enter the formula in a cell beside your list. Copy the formula down to the bottom of your data, and do a sort on the returned value. You should now have them sorted by color.

Example
GetColor("A1") Will return the colorindex value for cell A1.

HTH
Cal

PS- This formula will not work with conditional formatting.

Public Function GetColor(R As Range)
GetColor = R.Interior.ColorIndex
End Function