As many developers, my eyes suffer from many hours spent on the screen. I like dark and colored syntax highlighting, but for my eyes this kind of contrast is another story.
I googled “syntax highlighting eyes” and found the Zenburn theme (official page http://slinky.imukuppi.org/zenburn/).
I have done a small adaptation to Xemacs from the Emacs theme. It can be found here (https://github.com/dbrock/zenburn-el/blob/master/zenburn.el)
The custom.el file is here (http://julien.boucaron.free.fr/xemacs/custom.el_ZENBURN)