Visual Studio Apollo Theme

Apollo brings warm, high-contrast dark and light palettes to Visual Studio 2022+ across the editor, environment chrome, and output surfaces.

_{Simulated preview. Application chrome and typography may vary; follow the visual checks below against the canonical palette.}

Important

This repository ships native themes/Apollo.vstheme and themes/Apollo Light.vstheme sources and deliberately does not produce a VSIX. Use a temporary Color Theme Designer project to load either without inventing an unverified extension package.

The public Apollo Dark variant keeps the existing unsuffixed identity in themes/Apollo.vstheme; Apollo Light keeps its existing light identity in themes/Apollo Light.vstheme.

Coverage

• Visual Studio 2022+ environment chrome and editor syntax.
• Diagnostics, active focus, search, selection, and current-statement cues.
• Command Window and Output Window categories.
• Deterministic generated output from the repository-owned palette snapshot.

Install

1. Install Visual Studio Color Theme Designer 2022.
2. In Visual Studio 2022, create a temporary VSTheme Project.
3. Close the generated theme editor, replace that project's generated .vstheme file with themes/Apollo.vstheme or themes/Apollo Light.vstheme, and reopen it from Solution Explorer.
4. Choose Preview for a temporary check or Apply to make that variant available to the IDE.

The designer does not document a direct standalone-file import command. The temporary project is therefore required to load and apply this source .vstheme without fabricating a VSIX. Keep a backup/export of your previous environment settings if you want to restore custom colors exactly.

Activate

After applying a theme, open Tools > Options > Environment > General and select Apollo or Apollo Light in the color-theme list. Restart Visual Studio if a tool window still caches old colors.

Visual verification

Open a C# solution and verify:

• Apollo uses canvas #141617 and text #cfbc97; Apollo Light uses paper #f9f5d7 and text #3c3836.
• Keywords and syntax errors are red; strings and saved changes are green.
• Types and methods use gold #fabd2f; properties/information use blue; constants use magenta; namespaces use cyan.
• Active focus/search/current-statement cues use gold; selection uses dark brown without reducing text readability.
• Solution Explorer, tool windows, tabs, menus, status bar, Command Window, and Output Window remain legible.
• Normal interface/editor text never uses restricted #665c54.

Uninstall or restore

Because this repository ships theme source rather than an installed extension, there is no Apollo entry in Manage Extensions. Select another color theme under Tools > Options > Environment > General to stop using Apollo, then delete the temporary VSTheme project if it is no longer needed.

Develop and validate

Portable generation and checks:

python3 scripts/generate.py
python3 scripts/generate.py --check
python3 scripts/check.py
python3 -m unittest discover -s tests -v
xmllint --noout --schema schemas/vstheme.xsd themes/Apollo.vstheme "themes/Apollo Light.vstheme"

Run one focused test with:

python3 -m unittest tests.test_theme.VisualStudioThemeTests.test_editor_status_colors_match_palette

On Windows, run the native .NET XML validation path:

pwsh -File scripts/validate.ps1

Both portable and Windows paths run in CI. Both .vstheme files are deterministic generated outputs; change mappings in scripts/generate.py and regenerate. Both palette snapshots must remain byte-for-byte canonical.

Why there is no VSIX

A correct Visual Studio theme VSIX needs a genuine extension/product identity, VSIX manifest, and Visual Studio SDK/MSBuild packaging project validated on Windows. No such identity or project was supplied, and inventing them would produce a misleading or unverified package. The native .vstheme is complete and loadable as source through a Color Theme Designer VSTheme project; Windows CI validates and stages it as the supported build artifact.

License

MIT. Copyright (c) 2026 D0n9X1n.