Ubuntu Bionic: gtk2 apps look bad

[manmath]

On my Ubuntu Bionic, gtk2 apps look really ugly. Have a look at the screenshot (attached) where nautilus looks fine, whereas artha (gtk2) looks ugly. Please suggest me a fix.
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[Frogs Hair]

I can't reproduce the effect . I don't think you would be missing any gtk2 or 3 theme engines on 18.04 which is all I find related to this issue on the web so far. Using Ambiance theme.

[again?]

I use xubuntu but booting to a live cd of Ubuntu 18.04 and installing artha it does not look like your pic.
Edit: Frogs Hair confirms that it is most likely some change you have made.

Are you using the default theme?
Try a different user account to check you have not set some user config.

[Dennis N]

Some gtk2 applications may require a specific theme engine installed to look right with certain gtk2 themes. Look for packages matching gtk2-engines* There are several.
(In Ubuntu 18.04, only two are installed by default. gtk2-engines-murrine and gtk2-engines-pixbuf)

[manmath]

Thank you all for coming to my rescue. The issue has been resolved. I'm sorry for not replying on time. Actually the issue was very trivial. While customizing the theme I had somehow disabled "Gnome Settings Daemon's xsettings plugin." After I enabled the same and rebooted the system it all back to normal.