Switch UI theme programatically Follow

In CLion, I have two UI themes to choose from: Default and Darcula. I like Default during day, Darcula at night.

Is there any way to switch between themes programatically, from external script or an IDE plugin?
Ideally, the change should be triggered by external event, for example depending on light sensor data or current time.

On Mac, I can run the following Apple Script:

activate application "CLion"

tell application "System Events"
 keystroke "," using command down
 delay 1.0
 key code 115 -- home
 key code 124 -- right
 key code 125 -- down (Appearance)
 key code 48 -- tab (Theme)
 key code 125 -- down (drop down)
 key code 125 -- down (Darkula)
 key code 36 -- enter
 key code 36 -- enter
end tell

It works, but the keypresses may not be registered due to various delays. Also I would like not to see the Preferences dialog at all, just switch the theme.

I've also played with LivePlugin, found UIManager.setLookAndFeel(), but that seems to be very low level and does not affect the Theme selector at all.

Is there any better, more reliable solution?