high contrast theming

[akosyakov]

Review how VS Code applies high contrast colors https://code.visualstudio.com/api/references/theme-color#contrast-colors and apply them similarly in Theia.

We leave it out from the initial theming.

[kittaakos]

Some issues are also listed here: #7353

• selection in the Explorer,
• border of the buttons in the dialogs,
• tbd

[kittaakos]

The context menu, in the browser example, is also broken:

[kittaakos]

[nitpick]: I think the border of the left side-bar is not aligned with the main menu bar:

[kaiyue0329]

In the Problems View, there is no border around the selected node.

In VS code,

In Theia,

(Arrow pointing to the selected node)

[kittaakos]

Editor and Explorer decorators always white with the HC theme. I would expect red and yellowish colors.

[kittaakos]

Also: #7489

[kittaakos]

Support for hover. VS Code:

TODO: Revisit whether we want to support it for dialog buttons or not. VS Code does not have any dialogs but they do not support it in the Explorer:

[kittaakos]

Difference between the editor error markers:
VS Code

Theia:

Maybe it is a TS issue.