The main thing that's hard going down this route is dark mode support. The Win32 USER and common controls just don't not support dark mode, but are actively hostile to it due to the amount of hardcoded light colors and backgrounds in the system. All of the system colors are light regardless of the dark/light system setting, highlights are hardcoded to light blue, disabled controls use a hardcoded color, half of the window messages for changing control colors are silently ignored with theming is enabled. Menus are among the more difficult to deal with as they require extensive owner draw.

On top of this, there are a small handful of system UIs that do support dark mode and make your program look inconsistent with dark mode regardless. Message boxes will switch to dark mode, and so will file dialogs -- which is a problem if you've used the Vista-style customization, as any syslinks will appear in a color of blue that's hard to read against the dark mode background.

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gzread 2 hours ago | parent [-]

First, dark mode is for people who set their screen brightness too high.

Second, win32 is designed with the ability to change all the default colors and you used to be able to do this by right clicking the desktop and selecting "properties". If dark mode doesn't follow this - just another symptom of Microsoft's siloing incompetence. The team that wrote dark mode may not have been aware that this feature existed because parts of the platform are so disconnected from other parts.

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ack_complete 2 hours ago | parent | next [-]

Dark mode for apps is a setting in the OS and a general expectation now, it's suboptimal to ship a new UI that doesn't support it. And, again, Win32 message boxes in your program will switch to dark mode whether you want them to or not.

Win32 controls ignoring system colors goes much farther back than dark mode being introduced in Windows 10. The theming engine that broke a lot of that functionality was introduced in Windows XP. Beyond that, there were always a few hardcoded colors like disabled gray text going back to Windows 95.

Dark mode ignoring Win32 system colors is not incompetence. It was _intentional_. Dark mode was introduced by the UWP side, which intentionally did not extend it to Win32. To this day, there is not even a Win32 API for desktop apps to query whether dark mode is even enabled. The official recommendation is to compute the luminance of the UWP foreground color setting:

https://learn.microsoft.com/en-us/windows/apps/desktop/moder...

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bigstrat2003 2 hours ago | parent | next [-]

Only a very small minority of users actually care about dark mode. It is not a general expectation for software, as loud as those users may be on forums like this one.

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localuser13 an hour ago | parent | next [-]

And how do you know this? I decided to check myself, looked for dark mode statistics on android, and:

>Dark mode is used by 81.9% of 2,500 Android users on their phones, in apps, and in other situations. 9.9% alternate between the light and dark

So it's the other way around. Only a very small minority of users actually care about light mode.

	▲	fireflash38 6 minutes ago \| parent [-]
		I think android is a big difference here. What about excel or Google sheets? Word? If you're building win32 you're not targeting android.

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jitl an hour ago | parent | prev [-]

On Apple platforms is very uncommon to find apps that only support light mode. The only one on my phone is the app for my old Chinese robot vacuum.

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ptx 2 hours ago | parent | prev [-]

But they had dark themes for the XP theming engine, e.g. the Zune theme, didn't they? They could make the dark mode switch to a dark theme for XP-style themed controls and configure dark colors for the Win32 system colors.

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lwkl 2 hours ago | parent | prev [-]

It is not. I have some issues with my eyesight and dark mode makes it easier to use a computer in some lighting conditions. So for me dark mode is an accessibility feature. And yes you could use the ugly recolor feature windows has but dark mode does the same thing and looks better most of the time cause a UI designer actually looked at it.