# Shadcn Form Validation

> Form field with validation

- Type: example, free and open source (MIT)
- Component: [Color Picker](https://reui.io/components/color-picker.md)
- Page: https://reui.io/components/color-picker/c-color-picker-15
- Docs (Base UI): https://reui.io/docs/components/base/color-picker.md
- Docs (Radix UI): https://reui.io/docs/components/radix/color-picker.md
- MCP: `get_example("c-color-picker-15")`
- Registry item: https://reui.io/r/styles/base-nova/c-color-picker-15.json
- Uses: Button, Color Picker, Field

## Best for

A plain HTML form read through FormData, where the picker posts under name and Field swaps its hint for the error

## Agent notes

- `onSubmit` only reads `brandColor` from `FormData` into local `saved` state; send it to your API there

## Install

```bash
npx shadcn@latest add @reui/c-color-picker-15
```

## About Shadcn Color Picker

### When to use

- Brand, accent and theme token settings kept as a hex, rgb or oklch string
- Label, text and highlight colors chosen from a fixed palette of named presets
- Design and drawing tools: fill and stroke inspectors, brush pickers, contrast checks and shade scales

### When not to use

- A whole settings, profile or data entry screen with many fields and a save bar: use the [Form blocks](https://reui.io/blocks/application/form.md)
- A full document writing surface with a formatting toolbar, lists and links: use the [Rich Text Editor blocks](https://reui.io/blocks/application/rich-text-editor.md)

### Agent notes

- `ColorPicker` renders no wrapper element, so its children lay out in the parent; `className` on it styles only the trigger it draws when given no children
- A value passed in any syntax `parseColor` reads is accepted, but the next change comes back written in the root `format`
- Without `alpha`, opacity in a passed value is ignored on screen and every value the picker emits is opaque

Every ReUI item has a twin like this one; the index is https://reui.io/llms.txt. Agents with the ReUI MCP (https://reui.io/docs/mcp) get the same guidance from the getters named above.