Title and menu bar color on windows
This is a great theme! However, in windows the title bar is still light colored and the menu bar (and also all menus) is the Rstudio dark blue, see puicture below:

From #8:
So, from what I can tell, RStudio's menu bar is outside the scope of what's customizable through injecting css into index.htm. The menu bar and editors (the four panes) are built using different frameworks; Qt is used for the menu bar, while Ace is used for the editors.
However, someone else has made a package that solves this problem! Check out rscodeio and let me know if this is what you expected the menu bar to look like.
I personally use rscodeio to change the menu bar. Unfortunately, however, I don't think changing the titlebar color through darkstudio is possible.
edit: and thanks!
I love this theme too, and have also had issues with the title bar still be blue, so I made a custom css for it that corrects for most of the non blue things.
If you go into Program Files\RStudio\resources\stylesheets\rstudio-windows-dark.qss and paste in the following, it'll fix it:
QMenuBar {
background-color: rgb(59, 59, 59);
border-bottom: 1px solid rgb(36, 36, 36);
}
QMenuBar::item {
color: rgb(240, 240, 240);
background-color: rgb(59, 59, 59);
padding: 3px 8px 2px 8px;
}
QMenuBar::item:selected {
color: white;
background-color: rgb(69, 69, 69);
}
QMenu {
background-color: rgb(59, 59, 59);
}
QMenu::item {
color: rgb(255, 255, 255);
}
QMenu::item:disabled {
color: rgb(148, 148, 148);
background-color: rgb(59, 59, 59);
}
QMenu::item:selected {
color: white;
background-color: rgb(69, 69, 69);
}
QMenu::item:selected:disabled {
color: rgb(148, 148, 148);
background-color: rgb(59, 59, 59);
}
Proof:
Before
After

@davidyshen Works beautifully! Thank you :)