From googling, i have seen some screenshots of a supposedly dark theme, but there is no mention of how achieve the dark theme.

Here are the screenshots:
http://kmymoney2.sourceforge.net/kmymon ... theme.html

Does anyone know?

KMyMoney does not provide any theming itself, it uses the theme chosen in your window manager. If you are using Plasma, that would be systemsettings5. Given that you found your examples on the ancient KMM sourceforge site, those specific themes may not even be available any more, but there are certainly plenty of dark themes out there for either Gnome, Plasma, or whatever you are using.

Thanks for your reply.

I am using Gnome, and with the dark theme turned on, some other apps become dark, but kmm is one app that doesn't inherit the dark theme.

All that white in kmm is blinding.