As I regularly check out new themes at store.kde.org, I noticed that in the screenshots of modern themes, the dolphin panel with the folder list does not have alternating backgrounds as on mine.
I’m not sure anymore when exactly this alternating background was introduced, but it was somewhere during the time of Plasma 5.2x.x. I accepted it at the time as a change from upstream, but I’ve never liked it, and now that my eyes are getting a bit older again, I find that it’s actually counterproductive.
It does not appear to be theme-dependent — it appears in multiple themes — and I’ve looked all over the dolphin settings and the kvantum settings, but I cannot find any setting pertaining to this alternation between a dark background and a translucent one.
It’s also not in the color scheme, and for two reasons…:
My color scheme shows them both to have the same color.
kvantum themes don’t use the color scheme, because they are SVG-based.
Apparently there is a way to disable it, given that the themes at store.kde.org don’t show this effect, but for the life of me, I cannot find it. Ergo, I would appreciate it if some kind soul were to explain to me how to get rid of it.
P.S.: The alternation in background does not appear in the Places panel. It’s only in the folder list.
In System Settings go to Colors, select a color theme that’s editable, click the edit tab, in the Colors tab, you will see Color Set: and select View, Change the Alternate Background so it matches Normal Background. I use Save as, pick a name I like then apply the new theme.
Certainly with THAT colourscheme it is extremely annoying. I did flirt with having it set at a very low contrast - #2c2928 - #302d2c but overall I don’t really understand why it is deemed likely to ‘improve legibility’
So this is the case for not installing Global or pre-defined themes, instead opening Settings-colours and adjusting BackgroundAlternate and BackgroundNormal.
In the Colours it’s certainly possible to adjust the colours for the main window listing - I set mine to be the same, then I adjusted it for a very slight difference (just tweak a tad less bright, and a tad more hue for schemes with hue).
Generally though, sure - there should be toggles for every individual area where this is a thing.
You don’t see it in the Places panel, so toggling on the ‘Folders’ view should at least match the main list view.
Right now I’m at a loss to give a comprehensive list of where these can be adjusted or matched in the colours dialog… but subtle can be quite nice.
I just tried enabling the “Folder List” and without you having mentioned it, I probably wouldn’t have noticed the effect as it’s very subtle on this display (Breeze Dark theme). Which themes have you tried?
EDIT: I wonder how much that partial transparency is exaggerating (or even causing) the “effect”? … I turned off transparency in Konsole and Dolphin, etc.
But that’s just the thing, guys: it is already set to the same color for main and alternative. And that was also already the case in my previous application theme and its color scheme.
Besides, kvantum themes don’t follow the color scheme, because the colors are hard-coded in the theme itself — it’s SVG-based. But I’m pretty sure that the alternating background thing isn’t part of the theme. It’s probably some qt- or Frameworks-specific thing. It also does not occur anywhere else than in dolphin.
So there shouldn’t be any difference, and yet there is.
If you use a light background — I’ve only downloaded this particular wallpaper yesterday or the day before, and I’ve already switched to a darker one again — then that’s how dolphin looks, yes. It’s not ugly anywhere else, but of course, the wallpaper also plays a role in that.
I’ve already tried that. I set it to Breeze Dark and then back to Kvantum. It doesn’t make any difference. I’ve also already deleted ~/.config.Trolltech.conf, but that too doesn’t make any difference.
Never tried using kvantum on kde before, perhaps I’m doing it wrong.
After installing, the only kvantum themes I can find are in Application Style and Colours. After setting a theme and logging out and back in, dolphin is using the kvantum theme and the same method still works for me.
No, a kvantum theme must be loaded into the Kvantum Manager — it already contains a number of them, but if you download a new one, or a new global theme, then you must unpack the kvantum archive for that theme and point the Kvantum Manager at the folder. It will then import the theme and allow you to select it and tweak it.
I tried setting it in kvantum and it only applies to kvantum.
There’s nothing to select in the System Settings → Colours & Themes, apart from a couple of kvantum application themes (kvantum and kvantum-dark) and lots of kvantum colour themes.
If I select an application theme and log out and back in again then it applies the theme I set in kvantum manager. KvBrown in the pic I temporarily posted.
Yes, although you don’t have to log out. Just close the application, set the Application Style to kvantum , select a kvantum theme in the Kvantum Manager, and restart the application.
As I said, I tried getting the alternate color to be lighter, but it doesn’t make any difference at all.
Furthermore, the alternate color should actually be translucent, just like the main background, but instead it is opaque. I’ve checked every conceivable setting in Dolphin, the Kvantum Manager, the translucency section of the desktop effects in System Settings, the color scheme settings, but there just does not appear to be any way to do away with those alternating backgrounds.
Well, now that I’ve logged out and back in again, the added alpha channel has a few strange side-effects…
Several of the KDE applications show more translucency in certain areas now — which will take some getting used to, but it’s cool — but more importantly, the chromium menus — i.e. the context menus, the bookmark folder menus, and the hamburger menu on the right of the toolbar — are now completely transparent, without any color, and without any blur. The global menu menus on the other hand are fine and look as they should.
The only way around it is to switch the chromium appearance from qt to gtk, but then its colors no longer match my application style.
Adding an alpha channel — adding 
