This is a problem with a goodly number of Epson and other brand
printers. They never wrote driver updates for XP. If there is a driver
available for WIN 2000, that will probably work with XP. If not, then
you may well be stuck with the in box drivers from XP, and often they do
not support color, as they are meant to be utilitarian, mainly for text
printing applications.
If this is the case, consider sending Epson a note of displeasure. Only
they will be able to resolve this, and only if their is enough consumer
pressure.
Art