I have both the 8570 & 8650 printers. When I purchased my 8570, it came with a rainbow starter pack of ink cubes. The box states "For the Colorqube 8570/8870 solid ink printers." I see also that the specs on my maintenance kit works for both also. So here's my question .... Can I use 8870 ink in my 8570 printer? Seems to me if the starter ink pack works in both, the ink should interchange. Am I correct?