Test shows different results

[Quaraxkad]

Windows Version: 11

Question
This probably isn't an issue with msstyleEditor itself, but I don't know anywhere else were people would be able to follow along with editing msstyle files, so I figured this is the best place to get help!

I used msstyleEditor to modify the default aero.msstyles. I wanted to use the scrollbars from aerolite.msstyles. So I changed all the scrollbar properties in aero to match those in aerolite. When I click the test button, I get (almost) exactly what I wanted.

For comparison, here is my "unmodified" style as shown in Control Preview. This is the result of whatever Windows customizations have allowed:

Then, this is the untouched aero.msstyle using the Test button. For some reason the active title bar changes to dark grey instead of blue (it's still the foreground window, background windows are a lighter grey), but that's a problem for later, it's not what I'm asking about now (unless it's related!).

And here is aerolite.msstyle using Test. Not sure why Buttons are messed up here, but I'm also not concerned about that because I'm not using that style.

And this is my modified aeroclassicscroll.msstyle using Test. This is essentially everything from aero, except scrollbars from aerolite.

Everything in aeroclassicscroll looks perfect (with the exception of the title bar color). But when I apply this style using SecureUx ThemeTool, this is what the Control Preview windows looks like:

I have compared the entirety of both ScrollBar and ScrollBarStyle in the app, and used Export Info to compare side-by-side, and both Scrollbar classes are identical between aerolite and aeroclassicscroll. Everything else is identical between aero and aeroclassicscroll.

Anybody have any ideas why my scrollbars would be black in use, but not in testing?

[Undisputed00x]

This is actually an issue I'm facing as well. This is not just a problem with the scrollbar control, but more of a general issue with the "Test" feature of the msstyle editor. The msstyle test seems to be unstable and applies parts of the theme. This issue is also addressed in the latest win11 updates of 23H2 and 24H2.

[nptr]

I think I commented about this some time ago but can't find it. msstyleEditor applies the themes from a temporary directory using some undocumented, never officially supported function. Likely in an unintended way. Windows applies the themes with some other (also undocumented and inofficial) functions, but requires installation in the themes directory and all that goes along with it. I never root-cause analyzed it, but I suspect that the issues lies in that somewhere.

Ideally, msstyleEditor one day operates on a full theme and not just the visual style (.msstyles files). That might allow for a better "Test" feature and probably better font and string resource handling too.