Avalonia Pro Max/themes

Avalonia Theme Libraries

TL;DR Defaults

| You want | Use | |---|---| | Modern Microsoft / Windows-native feel | FluentTheme + FluentAvalonia | | Modern, opinionated flat (Linear-like) | SukiUI | | Clean Chinese-design-system look | Semi.Avalonia | | Material Design 3 | Material.Avalonia | | shadcn/ui-inspired developer aesthetic | ShadUI | | Rich enterprise control set | Ursa.Avalonia | | Just a slight upgrade over built-ins | Citrus.Avalonia | | Retro Windows 9x | Classic.Avalonia | | Fallout Pip-Boy / themed novelty | Pipboy.Avalonia | | Pure custom (no library) | FluentTheme only + your own ControlThemes |

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Recommendation Matrix by Product Type

| Product | Best fit | Why | |---|---|---| | Internal tools / admin / dashboards | FluentAvalonia + FluentTheme | NavigationView, InfoBar, TeachingTip ready; matches Windows desktop expectation | | Cross-platform consumer app | SukiUI or Semi.Avalonia | Look identical on Win/macOS/Linux, modern flat | | Mobile-first cross-platform | Semi.Avalonia + custom tokens | Lightweight, works well at small sizes | | Developer tool (IDE, terminal, db client) | SukiUI or ShadUI | Dark-first, low-chrome, accent-driven | | Material-spec product | Material.Avalonia | True MD3 compliance | | Enterprise B2B with many forms / data | Ursa.Avalonia | Pre-built form, tag, badge, drawer, time picker, etc. | | Game launcher / creative app | SukiUI + custom palette | High-contrast, flexible | | Migration from WPF (minimum visual change) | FluentTheme only | Closest to legacy Windows look without Material weirdness |

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FluentTheme (built-in baseline)

Always start here unless you have a strong reason. Ships with Avalonia, no extra NuGet.

Pair with RequestedThemeVariant="Default" to follow OS.

Customize the FluentTheme accent via well-known resource keys:

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FluentAvalonia

WinUI3-style controls + accent system. Best companion to FluentTheme.

dotnet add package FluentAvalonia

Key controls: NavigationView, Frame, InfoBar, TeachingTip, CommandBar, Expander (rich), ContentDialog, FAComboBox, NumberBox, TabView, SettingsExpander.

Use instead of FluentTheme (FluentAvaloniaTheme already includes Fluent base).

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SukiUI

Opinionated flat dark-friendly theme, modern look. Includes own controls and dialog system.

dotnet add package SukiUI

Wrap windows in SukiWindow for the chromeless title bar:

Dialogs: ISukiDialogManager injected into ViewModel.

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Semi.Avalonia

Port of Semi Design (ByteDance). Clean, dense, great for forms.

dotnet add package Semi.Avalonia

Often paired with Ursa.Avalonia (same author) for extra controls (TagInput, IconButton, Drawer, TimelineItem, Toast).

dotnet add package Irihi.Ursa
dotnet add package Semi.Avalonia.Ursa

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Material.Avalonia

True Material Design 3.

dotnet add package Material.Avalonia
dotnet add package Material.Avalonia.DataGrid    
dotnet add package Material.Icons.Avalonia

Use Material.Icons.Avalonia for the icon set:

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ShadUI

shadcn/ui-inspired styling for Avalonia. Currently community-driven; check repo for latest install.

Aesthetic: minimal, neutral grays, single accent, subtle shadows, generous radius. Ideal for developer-facing tools.

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Ursa.Avalonia

Stand-alone full UI library (also bridges with Semi). Adds: Form, Tag, IconButton, Drawer, Skeleton, Toast, Banner, Pagination, KeyGestures, color picker, time picker, calendar, date picker, etc.

dotnet add package Irihi.Ursa

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Citrus.Avalonia

Light styling pack — keeps native controls but modernizes their visuals. Good for "tweak the defaults" projects.

dotnet add package Citrus.Avalonia

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Classic.Avalonia / Pipboy.Avalonia / Neumorphism.Avalonia / WPFDarkTheme

Niche aesthetics — ship as primary theme only when the app's identity demands it. Don't combine with Fluent/Material.

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Combination Rules

Allowed (tested combinations):

• FluentTheme + FluentAvalonia → use FluentAvaloniaTheme (it includes Fluent base)
• FluentTheme + Ursa.Avalonia
• Semi.Avalonia + Ursa.Avalonia (+ Semi.Avalonia.Ursa bridge)
• Any theme + Citrus.Avalonia for table/scroll polish
• Any theme + an icon library (Lucide.Avalonia, Material.Icons.Avalonia, Projektanker.Icons.Avalonia)

Forbidden (visual chaos):

• Material.Avalonia + FluentAvaloniaTheme (different design systems)
• SukiUI + Material.Avalonia
• More than one base theme of the same kind
• Mixing two icon families in the same view (pick one per app)

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Theme Selection Workflow

1. Identify product type → pick from matrix above.
2. Install minimum NuGets (1 base theme, optional 1 control library, 1 icon library).
3. Set RequestedThemeVariant="Default" so OS preference wins by default.
4. Override only the accent color + neutral surface colors via theme dictionaries.
5. Build app-specific Styles in avares://MyApp/Styles/ — never modify the theme NuGet.
6. Test light and dark variant before committing.

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Common Mistakes

• Importing two base themes — ` after ` causes brush conflicts.
• Hardcoding theme NuGet brushes in views — they may be renamed in next version. Wrap them in your own semantic tokens.
• Forgetting RequestedThemeVariant="Default" — app stays in light mode regardless of OS setting.
• Restyling default controls in App.axaml when using SukiUI/Semi — overrides their styles and breaks intended look. Use Style classes instead.
• Copy-pasting theme brush keys without checking version — keys like SystemAccentColor exist in FluentTheme but not all alternatives.
• Wrapping a normal Window in SukiTheme without SukiWindow — content gets styled but the title bar stays native.

Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: linuxdevel
• Source: linuxdevel/Avalonia-skills
• License: MIT

Install and usage instructions live in the source repository linked above.