Eh... I don't think Greta and Trisha are the same babe. Greta has grayish eyes, whereas Trisha has rather dark brown / hazel eyes.
Greta:
http://galleries.payserve.com/1/0/11198/images/06.jpg
Trisha:
http://girls.twistys.com/preview/204/trisha_12.jpg
Or are those just extremely good colored contact lenses?
Trisha's lips are also somewhat thicker than Greta's and it doesn't look like the results of plastic surgery to me.