Unpack, then go to the folder Valium/gtk/Valium and move gtk-2.0 folder to ~/.themes/Valium.
My bad, had to name subfolders like gtk-theme, pekwm-theme etc or place a readme file into the archive ) - Aug 15 2010
if you looking on dark theme or on a preview from the light theme - of course, your eyes are just not ready for the contrast :)
But for me, from dark theme, with my monitor settings - almost all dark themes looks good :)
- Aug 15 2010