The old theme I made no longer works for the latest QupZilla (1.8), so here's the new version.
I have basically taken the default Linux theme, tweaked it a bit so it's using flat icons.
Author of Original Theme: David Rosca
Icons come from icon theme: BreezeRemix
---- Installation -----
Put this folder in /usr/share/qupzilla/themes/
Start/Restart QupZilla and pick the theme :-)