---
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title: Dynamsoft Document Viewer API Reference - Interface UnderlineStyle
keywords: Documentation, Dynamsoft Document Viewer, API Reference, Interface UnderlineStyle
breadcrumbText: Interface UnderlineStyle
description: Dynamsoft Document Viewer Documentation API Reference Interface UnderlineStyle Page
---

# UnderlineStyle

## Syntax

```typescript
interface UnderlineStyle {
    opacity?: number;
    borderColor?: string;
}
```

## Attributes

### borderColor

The borderColor style of annotation.

Default value: `#0E68F5`.

**Example**

```typescript
borderColor: "rgb(255,255,255)", 
```

**Remark**

Supported string value of `borderColor`:

- Named color, for example, `red`, `green`, etc.
- HEX(`#RRGGBB`), for example, `#ff0000`, `#008000`, etc.
- RGB(`rgb(red, green, blue)`), for example, `rgb(255, 0, 0)`, `rgb(0, 128, 0)`, etc.
- HSL(`hsl(Hue, Saturation, Lightness)`), for example, `hsl(0, 100%, 50%)`, `hsl(120, 100%, 25%)` ,etc.

### opacity

The opacity of the whole annotation. The value range is [0,1], value which is greater than 1 will default to 1.

Default value: 1