I know there are infinite dark themes available over internet and I have googled it so much and tried almost all dark themes. However, no theme is having 100% black colour, it is always a shade of black (emitting some amount of light) not pitch black or perfectly black. Even in the pitch black coloured theme or high contrast theme, it is only a shade of black, it still emits light like dark grey colour but not absence of light. What I am referring to is the colour in MS DOS background for example. That 100% dark colour theme is available nowhere. Now I think that may be the minimum can be done is somehow change any existing dark them to that colour by some system modification (I do not know how but I wish to know) or the better still if someone knows such a theme, please share link with me. I will thank you very much for this help. Thanks.
Edit. For a reference I am posting this sample dark terminal screenshot. This is only a example screenshot, original dark/black will look exactly like background of MS DOS.
Edit: Some users have asked me to try Kubuntu KDE, but this does not answer the question. Reason: What KDE offers, Ubuntu also offers. I am attaching a screenshot of Orchis them which I am currently using and is giving equal or more darkness than KDE. But it is not near to what I am seeking in the question. The question is very clear on this. I have also attached screenshot of the reference colour above. And here is what I have been able to achieve till now:
P.S. This is a potentially challenging & interesting question. :)
125 Answers
Try Kubuntu (KDE)...
You have a great deal of control over every aspect of the UI.
Here are screenshots of the process in Kubuntu 19.10...
Open System Settings.
Select Colors option.
Select the theme you want to edit, and click the "pencil" icon.
Select the UI component you want to change.
Select the new color.
However, no theme is having 100% black colour, it is always a shade of black (emitting some amount of light) not pitch black or perfectly black. Even in the pitch black coloured theme or high contrast theme, it is only a shade of black, it still emits light like dark grey colour but not absence of light.
Even with an MS DOS background with {Hue, Val, Sat, R, G, B} = {0, 0, 0, 0, 0, 0} i.e. "perfect black" as color, you'll still have light emissions as typical monitor panels have backlight.
To really obtain no light emission for black, use an OLED monitor.
4If you want no light emission like MS-DOS, use a plain terminal, because that's what MS-DOS used. You can have that by entering a tty session, no GUI with mouse pointer, bells and whistles, by hitting Ctrl+Alt+F3 at your login screen. You will be asked to login by entering your username and password, and then use it like any regular terminal.
Other than this, there is no theme that is perfectly dark. This is also not perfectly dark too, as you are still seeing the text with green/white fonts.
3You can use the dark theme in Ubuntu, change it to transparent and change the wallpaper to this:
Finally after a lot of search, I have found something near to what I was looking for. However, there is still scope for improvement in this theme.
In spite of being a beautiful theme, there are low ratings. I believe this is because it is not visible to users when we browse for themes from tweaks->appearance->themes despite saving theme in user/share/themes folder. I installed it using appimagelauncher and Pling-store. I am keeping this question open because I believe a still better answer may be possible.
Edit: This theme is very close now: (WatchOS theme of Mac - simply great)
