Why is there a slight color variance since I installed new ink cartridges?

• We are aware that some of our customers use special color matching techniques to precisely calibrate the color performance of Epson Stylus Photo printers. We are alerting such customers of a change in manufacturers of dye components used in the color ink that results in a very slight change in the output from Epson Stylus Photo 870, 875, and 1270 printers. This slight change would not be descernible with printers less capable of continuous tone printing, and most users of Epson Stylus Photo printers will also not notice any changes in color performance.
  
  Photographers who are particularly discerning, however, may notice that colors such as blue are very slightly more vivid and gray tones are very slightly cooler. This change affects T008201 and T009201 cartridges. The affected cartridges have lot numbers that begin with the letter "A".