fix(design-system): default colors for some of the icons

[kulmann]

Description

I noticed that some of the default colors for icons in the design system are not our theme default. Set them in the design system tokens now (where the defaults belong) and will delete them from the theme.json in the opencloud repo as soon as we brought a pre-release of web with the new defaults to the opencloud repo.

FTR: I just copied these colors:
https://github.com/opencloud-eu/opencloud/blob/df6fb3384f2089bade6c36a11497432f635cb570/services/web/assets/themes/opencloud/theme.json#L150

Types of changes

• Bugfix
• Enhancement (a change that doesn't break existing code or deployments)
• Breaking change (a modification that affects current functionality)
• Technical debt (addressing code that needs refactoring or improvements)
• Tests (adding or improving tests)
• Documentation (updates or additions to documentation)
• Maintenance (like dependency updates or tooling adjustments)

[Copilot]

Pull Request Overview

This PR aligns the default icon colors in the design-system tokens with the OpenCloud theme defaults, preparing removal from theme.json.

• Updated several icon color values in color.yaml to match theme defaults.

Comments suppressed due to low confidence (2)

packages/design-system/src/tokens/ods/color.yaml:5

• The updated icon color tokens lack associated regression tests. Consider adding or updating snapshot or visual regression tests to validate the new default colors.

      value: rgb(77, 126, 175)

packages/design-system/src/tokens/ods/color.yaml:5

• [nitpick] Document in code comments or in the design-system documentation that these icon color tokens align with the theme defaults and explain the rationale for these changes.

      value: rgb(77, 126, 175)