border-block-start-color

The border-block-start-color CSS property defines the color of the logical block start border of an element, which maps to a physical border color depending on the element's writing mode, directionality, and text orientation. It corresponds to the border-top-color, border-right-color, border-bottom-color, or border-left-color property depending on the values defined for writing-mode, direction, and text-orientation.

It relates to border-block-end-color, border-inline-start-color, and border-inline-end-color, which define the other border colors of the element.

Initial value	currentcolor
Applies to	all elements
Inherited	no
Media	visual
Computed value	computed color
Animation type	discrete
Canonical order	the unique non-ambiguous order defined by the formal grammar

Syntax

border-block-start-color: blue;
border-block-start-color: #4c5d21;

Values

<'border-color'>

See border-color

Formal syntax

<'color'>
where 
<color> = <rgb()> | <rgba()> | <hsl()> | <hsla()> | <hex-color> | <named-color> | currentcolor | <deprecated-system-color>
where 
<rgb()> = rgb( <rgb-component>#{3} )
<rgba()> = rgba( <rgb-component>#{3} , <alpha-value> )
<hsl()> = hsl( <hue>, <percentage>, <percentage> )
<hsla()> = hsla( <hue>, <percentage>, <percentage>, <alpha-value> )
<named-color> = <ident>
<deprecated-system-color> = ActiveBorder | ActiveCaption | AppWorkspace | Background | ButtonFace | ButtonHighlight | ButtonShadow | ButtonText | CaptionText | GrayText | Highlight | HighlightText | InactiveBorder | InactiveCaption | InactiveCaptionText | InfoBackground | InfoText | Menu | MenuText | Scrollbar | ThreeDDarkShadow | ThreeDFace | ThreeDHighlight | ThreeDLightShadow | ThreeDShadow | Window | WindowFrame | WindowText
where 
<rgb-component> = <integer> | <percentage>
<alpha-value> = <number>
<hue> = <number>

Example

HTML Content

<div>
  <p class="exampleText">Example text</p>
</div>

CSS Content

div {
  background-color: yellow;
  width: 120px;
  height: 120px;
}

.exampleText {
  writing-mode: vertical-lr;
  border: 10px solid blue;
  border-block-start-color: red;
}

Specification

Specification	Status	Comment
CSS Logical Properties Level 1 The definition of 'border-block-start-color' in that specification.	Editor's Draft	Initial definition

Browser compatibility

[1] Available since Gecko 38, but behind the preference layout.css.vertical-text.enabled, disabled by default. The preference has been removed in Gecko 51 and this property cannot be disabled since this version.

See also

• The mapped physical properties: border-top-color, border-right-color, border-bottom-color, and border-left-color
• writing-mode, direction, text-orientation