I am in the process of flushing my 7900 to remove the color inks before loading PiezoPro inks. In my Green and Orange slots I've had PF installed for over 6 months. Now I've installed PF in the remaining slots. I've pretty much removed all the color now after three INIT FILLs, but when I print 100% density bars of all 10 colors on a sheet of paper I'm noticing that the Green and Orange bars are noticeably lighter in pink color. Is this due to fading of the dye or maybe something else?