Are there any programs that implement iOS 26 icon styles (Light, Dark, Clear and Tinted) on other platforms (preferrably Windows and Linux, but can ...

If you’re referring to having customizable icon silhouettes, Android has been doing that for a while with Material Design, which has gotten old at this point.

I don’t believe any desktop environment behaves similarly because they don’t have a dominant app store and OS-level app standards encouraging design compliance like Android/iOS do.

You can get icon packs that are darker or lighter than the default icons, but afaik there is no way to get transparent liquid glass-like icons