# outline-color

> Sets `outline-color` alone, so a state such as `[aria-invalid]` can tint an outline while the width and style already in effect stay in force.

```ts
import { outlineColor } from "@sdxc/u/color";
```

Sets `outline-color` alone, so a state such as `[aria-invalid]` can tint an
outline while the width and style already in effect stay in force. With no
argument it resolves the system default ring color.

## Quick reference

Every documented call, beside the CSS it emits.

| Call | CSS |
| --- | --- |
| `u.outlineColor()` | `css({ outlineColor: "var(--ui-ring, Highlight)" })` |
| `u.outlineColor("danger")` | `css({ outlineColor: "var(--ui-danger-ring)" })` |

## Examples

### Basic example

Use `outlineColor` to set only the color of an outline, leaving its width and style to other calls:

```tsx
<div mix={[...]}>
	<div mix={[outlineWidth(2), outlineStyle("solid"), outlineColor(), ...]}>
		outlineColor()
	</div>
	<div mix={[outlineWidth(2), outlineStyle("solid"), outlineColor("success"), ...]}>
		outlineColor("success")
	</div>
	<div mix={[outlineWidth(2), outlineStyle("solid"), outlineColor("danger"), ...]}>
		outlineColor("danger")
	</div>
</div>
```

### Applying on a state

Wrap `outlineColor` in a state, like `invalid()`, to recolor an outline only in that state. Type something that is not an email and leave the field:

```tsx
<input
	type="email"
	placeholder="you@example.com"
	aria-label="Email"
	mix={[outlineWidth(2), outlineStyle("solid"), invalid(outlineColor("danger")), ...]}
/>
```

## Applying on a state

Wrap the call in a state utility to scope it to one selector.

```ts
u.hover(u.outlineColor())
```

## Responsive design

Wrap the call in a container query to scope it to one width.

```ts
u.at("md", u.outlineColor())
```

## Customizing your theme

### Customizing colors

Define a palette as `--ui-color-{name}-{50..950}` and map a tone onto it with the `--ui-{tone}-*` variables, the way `theme.css` maps the built-in ones:

```css
:root {
	--ui-color-info-50: oklch(0.97 0.02 230);
	--ui-color-info-200: oklch(0.88 0.06 230);
	--ui-color-info-500: oklch(0.62 0.16 230);
	--ui-color-info-600: oklch(0.52 0.18 230);
	--ui-color-info-900: oklch(0.3 0.1 230);

	--ui-info-bg-tint: var(--ui-color-info-50);
	--ui-info-bg-solid: var(--ui-color-info-600);
	--ui-info-fg: var(--ui-color-info-600);
	--ui-info-fg-muted: var(--ui-color-info-500);
	--ui-info-fg-emphasis: var(--ui-color-info-900);
	--ui-info-fg-on-solid: white;
	--ui-info-border: var(--ui-color-info-200);
	--ui-info-border-strong: var(--ui-color-info-600);
	--ui-info-ring: var(--ui-color-info-500);
}
```

```ts
declare module "@sdxc/u" {
	interface ColorPalettes {
		info: true;
	}
	interface SemanticTones {
		info: true;
	}
}
```

The new name is then accepted wherever the scale is:

```ts
outlineColor("info")
```

## Signature

```ts
u.outlineColor(value?: ColorValue | (string & {}))
```