[Bug]: Theme color not applied properly to icons

[SMH17]

⚠️ This issue respects the following points: ⚠️

• This is a bug, not a question or a configuration/webserver/proxy issue.
• This issue is not already reported on Github OR Nextcloud Community Forum (I've searched it).
• Nextcloud Server is up to date. See Maintenance and Release Schedule for supported versions.
• I agree to follow Nextcloud's Code of Conduct.

Bug description

After the recent upgrade to Nextcloud 28 the theme color for icons isn't applied correctly anymore.

In this picture you can see the folder icon color correctly matches the theme color, archive and document icons ignore the selected color.

Steps to reproduce

1. Select a custom theme color
2. Upload a compressed archive
3. Check the icon color in nextcloud web GUI

Expected behavior

Theme color should be applied consistently to choice.

Installation method

Community Manual installation with Archive

Nextcloud Server version

28

Operating system

Debian/Ubuntu

PHP engine version

PHP 8.2

Web server

Apache (supported)

Database engine version

MariaDB

Is this bug present after an update or on a fresh install?

Update

[SMH17]

After the update to 28.0.2 the theme color is totally ignored even for folders and selection highlight.

This bug can be reproduced when it is selected "Dark Theme" in "Appearance and accessibility settings".

[susnux]

I think this might happen due to some places that still use the primary color instead of the every-where-else-used primary-element color.

[skjnldsv]

server/lib/private/Preview/MimeIconProvider.php

Lines 85 to 88 in 672923f

	// Previously, we used to pass this through Theming
	// But it was only used to colour icons containing
	// 0082c9. Since with vue we moved to inline svg icons,
	// we can just use the default core icons.

I guess some icons are still not fixed 🙈
I think we can either:

1. move mime icons to the default grey or their brand color (like docx being blue, pdf being red...)
2. add back mime icon theming (I think this doesn't really add much anyway and is over engineered)

[susnux]

In this picture you can see the folder icon color correctly matches the theme color, archive and document icons ignore the selected color.

I have to correct myself. This is by design.
Folders are color primary, while documents are by design always that blue.
Like pdf is always red, documents are always blue.