Let the pictures say the story. The one on the left is the HTC DIAMOND and the one on the right is the HTC TOUCH PRO.
As you can see, on the HTC DIAMOND’s display has much more saturation and the image looks much more dense on the Diamond’s display as compared to HTC TOUCH PRO.
Also, on the Diamond’s display, the white color is more whiter, while on Touch PRO’s display, the white appears as pale yellow although my camera was not able to differentiate effectively, but in person, the difference can easily be observed.
(one more image after the break)