# Custom styles
A **custom style** is a reusable bundle of visual guidelines that shapes how Eraser's AI styles the diagrams it generates for your team. Where an [AI preset](https://docs.eraser.io/docs/ai-presets) governs _what_ the AI produces, a custom style governs _how it looks_. Apply one, and every diagram the AI generates comes out on-brand without anyone editing it by hand.
A style bundles three things:
- **Style brief** – plain-language guidance the AI follows (tone, color usage, shape conventions)
- **Color palette** – your on-brand colors, each mapped to where it appears
- **Style defaults** – the default look of shapes, connectors, and text
Custom styles apply most powerfully to **freeform diagrams**, where the style's defaults drive shapes, connectors, and layout. You can apply a style alongside an [AI preset](https://docs.eraser.io/docs/ai-presets): the preset controls the content, the style controls the look.
## Creating a style
Open the **Styles** section of your team dashboard and choose **New style**. Give it a name and an optional description, then fill it out one of two ways.
**Generate from example diagrams.** Drop in a few diagrams that already look the way you want, and the AI deduces the palette, typography, and shape defaults for you – created instantly and fully editable afterward.
- Accepted files: **PNG, JPG, VSDX, drawio, PDF, or PPTX**
- Up to **5 files**, **10 MB** each
- Analysis usually takes **1-3 minutes** – keep the page open while it runs
If the AI can't read a coherent style, it tells you why and lets you try different files or start blank. (Generating from a pasted Eraser link is coming soon.)
**Start blank.** Create an empty style and fill in the three parts yourself.
## The three parts of a style
### Style brief
Plain-language guidance the AI follows when styling a diagram.
Keep it focused – a brief can be up to **300 words**, and a few unambiguous sentences steer the AI more reliably than a long list. For example:
- "Use blue for services, gray for infrastructure. Reserve red for anything security-related."
- "Prefer rounded rectangles. Use cylinders only for datastores."
Edit it in the **Brief** tab and choose **Save**.
### Color palette
The named colors the AI draws from.
Each color has a name and three **role colors** for where it appears:
| Role | Where it applies |
| ----------------- | ---------------------------------- |
| **Border / Icon** | Shape borders and icon color |
| **Shape fill** | The body fill of a shape |
| **Group fill** | The fill of a group, lane, or pool |
Adding a color seeds all three roles from one color you pick; each is then independently editable. Colors adapt automatically for dark mode. Manage them in the **Palette** tab – add, rename, adjust a swatch, or remove. Naming colors by meaning (_Service_, _Datastore_, _Security_) makes the brief's guidance easier to apply.
### Style defaults
The default look of everything that isn't color, applied to **freeform diagrams** and organized by element:
| Section | Examples |
| ---------------------- | --------------------------------------------------------------------------------- |
| **Shape** | Corners, border style/thickness, alignment, icon size, typeface, font size |
| **Group, lane & pool** | Title width, border, alignment, font size, typeface |
| **Icon** | Icon size, typeface, font size |
| **Textbox** | Font size, alignment, typeface |
| **Divider** | Line style, thickness, typeface, label size |
| **Relationship** | Connector style, line style/thickness, start/end arrowheads, typeface, label size |
Set values in the **Defaults** tab; anything you leave alone stays on Eraser's built-in default. A **live preview** shows how a sample diagram responds, and a **Reset** link restores any value.
## Setting a default style
Mark one style as the **team default** and it applies automatically to new AI sessions. Anyone can switch to a different style – or none – for a given diagram.
## Applying a style
Select a style from the **style dropdown** in the AI sidebar before you generate. Styles are independent of AI presets, so you can apply **both at once** – each appears as its own chip.
## Access & permissions
| Action | Who can do it |
| ------------------------------ | --------------- |
| View and use styles | Any team member |
| Create, edit, or delete styles | Team admins |
| Set the default style | Team admins |