I don't think you guys quite get the point with High contrast.
A High Contrast Theme, has to have NO white in the background
it has to be BLACK on white letters, that is what they mean by "high contrast"
people who are legally blind, especially those with Glaucoma for example, the white backgrounds hurt our eyes. We need a totally black background theme, with bright bold white lettering.
That makes all the difference in the world, probably more so then magnification. and i should know, I've been legally blind since birth.
both magnification, and speech, are nice to have on occasion also, but I noticed on these themes you guys have, there ALL too white, you guys either need a total black theme with white bold lettering, or a way to invert brightness on those white themes. I mean viewing that white on google.com is bad enough most of the time. LOL its like looking in direct sunlight. not a thing we want to do.
specifically for XFCE, I'm not a big Gnome fan, hehe, but its better then KDE thats for sure,
those are my recommendations anyway,
See, i actually miss the old days of the CLI, before GUI's, where the black CLI on white letters was SO easy to read. This GUI stuff, makes accessibility suddenly an issue now when GUI's changed the familar black on white that I was comfortable with.