PlantUML Skinparam: Complete Styling and Theme Guide (2026)

PlantUML skinparam is the built-in styling system that controls colors, fonts, arrow styles, borders, and shadows across every diagram type. It works alongside the built-in theme library — skinparam provides precise property-level control, while themes apply a complete visual preset in a single line.

This guide covers the full plantuml skinparam property reference — color overrides, font settings, per-diagram-type styling, dark themes, the sketchy hand-drawn style, and how skinparam compares to the newer style tag syntax. Every example in this guide is ready to copy and test.

Test any plantuml skinparam code immediately in our free PlantUML generator online — no Java install required. Paste any code block, click Generate, and see the styled result in seconds.

What Is PlantUML Skinparam and How Does It Work?

PlantUML skinparam is a declarative styling command that overrides default visual properties at the diagram or element level. You write skinparam PropertyName value inside your diagram definition and PlantUML applies the style to all matching elements. Properties are camelCase and combine element type with property name.

The full plantuml skinparam reference is documented at plantuml.com/skinparam. There are two layers of styling in PlantUML:

Skinparam overrides always win over theme defaults. You can combine !theme with skinparam to use a theme as a base and then fine-tune specific properties — for example, applying !theme cerulean and then overriding just the arrow color with a brand hex.

PlantUML Skinparam Color Properties: Background, Border and Arrow

Color values in plantuml skinparam use hex codes (#rrggbb or #rgb), named HTML colors (red, blue), or transparent. There is no support for rgba values in skinparam — use hex codes with solid colors only. The table below lists the most-used global and per-element color properties.

Global Color Properties

Color Properties by Element Group

PlantUML Skinparam Font: Name, Size, Color and Style

Font properties follow the same ElementType + PropertyName pattern. Global font settings apply to all text in the diagram. You can override per element type — for example, setting a larger font only for class diagram headers while keeping body text at the default size.

@startuml
skinparam FontName "Segoe UI"
skinparam FontSize 13
skinparam FontColor #1e293b
skinparam TitleFontSize 18
skinparam TitleFontStyle Bold
skinparam ArrowFontSize 11

title User Login Flow

Alice -> Bob : POST /login
Bob --> Alice : 200 OK + token
@enduml

PlantUML Skinparam for Sequence Diagrams

Sequence diagrams have the widest skinparam support of any diagram type. You can control every visual element — participant boxes, activation bars, arrow colors and thickness, divider backgrounds, alt/loop frame fills, and note styling.

@startuml
skinparam ParticipantBackgroundColor #dbeafe
skinparam ParticipantBorderColor #1a56db
skinparam ParticipantFontColor #0c1f4a
skinparam SequenceArrowColor #1a56db
skinparam SequenceArrowThickness 2
skinparam SequenceGroupBackgroundColor #f1f5f9
skinparam SequenceGroupBorderColor #cbd5e1
skinparam LifelineBorderColor #93c5fd
skinparam NoteBackgroundColor #eff6ff
skinparam NoteBorderColor #1a56db
skinparam Shadowing false

Alice -> Bob : Request
activate Bob
note right of Bob : Processing
Bob --> Alice : Response
deactivate Bob
@enduml

PlantUML Skinparam for Class and Component Diagrams

Class and component diagrams share the same general property naming pattern. Class diagrams add header-specific properties for the class name bar. Component diagrams add interface styling. Both respond to the global color and font properties as well as their own per-element overrides.

Class Diagram Skinparam

@startuml
skinparam ClassBackgroundColor #eff6ff
skinparam ClassBorderColor #1a56db
skinparam ClassHeaderBackgroundColor #1a56db
skinparam ClassHeaderFontColor #ffffff
skinparam ClassFontColor #0c1f4a
skinparam ClassFontSize 13
skinparam ArrowColor #374151
skinparam Shadowing false
skinparam RoundCorner 6

class User {
  +String name
  +String email
  +login()
}
class Admin {
  +resetPassword()
}
User <|-- Admin
@enduml

Component Diagram Skinparam

@startuml
skinparam ComponentBackgroundColor #dbeafe
skinparam ComponentBorderColor #1a56db
skinparam ComponentFontColor #0c1f4a
skinparam InterfaceBackgroundColor #1a56db
skinparam InterfaceFontColor #ffffff
skinparam PackageBackgroundColor #f8fafc
skinparam PackageBorderColor #94a3b8
skinparam ArrowColor #374151
skinparam Shadowing false

package "Backend" {
  [API Gateway]
  [User Service]
}
() "UserAPI"
[API Gateway] --> [User Service]
[User Service] - "UserAPI"
@enduml

PlantUML Skinparam Themes: Full List and How to Apply Them

Themes in PlantUML are pre-built skinparam bundles. Apply any theme with !theme THEME_NAME as the first line after @startuml. You can then override individual properties using standard skinparam after the theme declaration — your skinparam lines always win over the theme defaults.

The full plantuml skinparam theme list contains 40+ built-in options. Here are all currently available themes:

Preview all themes visually before choosing — the PlantUML themes gallery shows each theme applied to the same sequence diagram so you can compare styles at a glance.

Dark Mode and High-Contrast Themes: Monokai, Nord and Dracula

PlantUML does not include official Monokai, Nord, or Dracula themes by name, but several built-in themes produce equivalent dark aesthetics. The closest built-in dark themes are cyborg, hacker, neon, crt-amber, crt-green, and blueprint. You can also build a custom dark theme entirely with skinparam.

Built-in Dark Theme Options

Custom Dark Theme with Skinparam

@startuml
' Custom dark theme approximating Monokai / Nord
skinparam backgroundColor #272822
skinparam ArrowColor #66d9e8
skinparam ParticipantBackgroundColor #3e3d32
skinparam ParticipantBorderColor #66d9e8
skinparam ParticipantFontColor #f8f8f2
skinparam ClassBackgroundColor #3e3d32
skinparam ClassBorderColor #a6e22e
skinparam ClassFontColor #f8f8f2
skinparam ClassHeaderBackgroundColor #1e1f1c
skinparam NoteBackgroundColor #1e1f1c
skinparam NoteBorderColor #75715e
skinparam Shadowing false
skinparam FontName "Courier New"

Alice -> Bob : authenticate
Bob --> Alice : token
@enduml

Sketchy and Hand-Drawn Style for Presentations

The sketchy theme renders diagrams in a hand-drawn, marker-on-whiteboard style — ideal for early-stage architecture discussions, client presentations, and any context where you want to signal that the design is still evolving. The sketchy-outline variant produces the same effect without filled backgrounds.

@startuml
!theme sketchy

title Team Meeting — Draft Architecture

[Frontend] --> [API]
[API] --> [Database]
[API] --> [Cache]

note right of [API]
  Still deciding on
  Redis vs Memcached
end note
@enduml

You can also achieve the hand-drawn look without the full theme using a single skinparam property: skinparam HandWritten true. This uses a built-in rough rendering algorithm and applies to all diagram types without changing any color settings.

PlantUML Skinparam vs the New style Tag Syntax

PlantUML 2.x introduced a CSS-like style tag as an alternative to plantuml skinparam. It uses selector-based syntax — you define a class name starting with a dot and assign properties inside curly braces. Elements then reference the style with a stereotype. Both approaches coexist in current PlantUML versions.

@startuml
' New style tag syntax (PlantUML 2.x+)
style .highlighted {
  BackgroundColor: #dbeafe
  BorderColor: #1a56db
  FontColor: #0c1f4a
}

class User <<highlighted>> {
  +login()
}
class Order {
  +submit()
}
User "1" *-- "many" Order
@enduml

For maximum compatibility across VS Code extensions, Confluence plugins, GitLab renderers, and CI/CD pipelines, use standard skinparam syntax. Reserve the style tag for environments where you can confirm PlantUML 2.x is running.

Reusable Team Stylesheets and Shared Config Files

The most efficient way to keep all your team's diagrams visually consistent is to centralise all skinparam settings in a shared .iuml file stored in your repository. Every diagram then includes this file with a single line — and style changes propagate automatically to every diagram in the project.

Creating a Team Stylesheet

' File: /docs/styles/team-style.iuml
' Include in any diagram with: !include ../styles/team-style.iuml

skinparam backgroundColor #ffffff
skinparam ArrowColor #1a56db
skinparam ArrowFontColor #374151
skinparam ParticipantBackgroundColor #dbeafe
skinparam ParticipantBorderColor #1a56db
skinparam ParticipantFontColor #0c1f4a
skinparam ClassBackgroundColor #eff6ff
skinparam ClassBorderColor #1a56db
skinparam ClassHeaderBackgroundColor #0c1f4a
skinparam ClassHeaderFontColor #ffffff
skinparam ComponentBackgroundColor #dbeafe
skinparam ComponentBorderColor #1a56db
skinparam PackageBackgroundColor #f8fafc
skinparam PackageBorderColor #94a3b8
skinparam NoteBackgroundColor #eff6ff
skinparam NoteBorderColor #1a56db
skinparam Shadowing false
skinparam RoundCorner 8
skinparam FontName "Segoe UI"
skinparam FontSize 13

Using the Shared Stylesheet

@startuml
!include ../styles/team-style.iuml

title User Authentication Flow

Alice -> Bob : POST /login
Bob --> Alice : 200 + token
@enduml

For teams that want to preview and validate skinparam styling without running a local PlantUML install, our free PlantUML generator online renders any skinparam configuration instantly in the browser. Paste the full diagram code including !theme and all skinparam lines to see the output.

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