All answers on similar questions talk about the editor's colors. The icls files you can download are also for the editor only. I would like to change the UI colors. The supplied Darcula scheme is the only dark one but it is unreadably with its light gray on medium gray text.
You can only do so by modifying the source code of Android Studio. The two currently available look & feels include a lot of custom painting, colors and icons, so it's not feasible to provide the possibility to customize them through the UI.