background-color

CSS Backgrounds

The CSS background properties are used to add background effects for elements.

In these chapters, you will learn about the following CSS background properties:

• background-color
• background-image
• background-repeat
• background-attachment
• background-position
• background (shorthand property)

CSS background-color

The background-color property specifies the background color of an element.

Example

The background color of a page is set like this:

With CSS, a color is most often specified by:

• a valid color name — like «red»
• a HEX value — like «#ff0000»
• an RGB value — like «rgb(255,0,0)»

Look at CSS Color Values for a complete list of possible color values.

Other Elements

You can set the background color for any HTML elements:

Example

Here, the ,

, and elements will have different background colors:

div background-color: lightblue;
>

Opacity / Transparency

The opacity property specifies the opacity/transparency of an element. It can take a value from 0.0 — 1.0. The lower value, the more transparent:

Example

Note: When using the opacity property to add transparency to the background of an element, all of its child elements inherit the same transparency. This can make the text inside a fully transparent element hard to read.

Transparency using RGBA

If you do not want to apply opacity to child elements, like in our example above, use RGBA color values. The following example sets the opacity for the background color and not the text:

You learned from our CSS Colors Chapter, that you can use RGB as a color value. In addition to RGB, you can use an RGB color value with an alpha channel (RGBA) — which specifies the opacity for a color.

An RGBA color value is specified with: rgba(red, green, blue, alpha). The alpha parameter is a number between 0.0 (fully transparent) and 1.0 (fully opaque).

Tip: You will learn more about RGBA Colors in our CSS Colors Chapter.

Example

The CSS Background Color Property

Источник

background-color

Определяет цвет фона элемента. Хотя это свойство не наследует свойства своего родителя, из-за того, что начальное значение устанавливается прозрачным, цвет фона дочерних элементов совпадает с цветом фона родительского элемента.

Синтаксис

background-color: | transparent | inherit

Значения

transparent Устанавливает прозрачный фон. inherit Наследует значение родителя.

HTML5 CSS2.1 IE Cr Op Sa Fx

       
Lorem ipsum dolor sit amet
 
Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed diem nonummy nibh euismod tincidunt ut lacreet dolore magna aliguam erat volutpat.
  

В данном примере для элементов веб-страницы применяется три различных способа задания фонового цвета. Результат примера показан на рис. 1.

Рис. 1. Применение background-color

Объектная модель

[window.]document.getElementById(» elementID «).style.backgroundColor

Браузеры

Internet Explorer до версии 7.0 включительно не поддерживает значение inherit .

Источник

background-color

The background-color CSS property sets the background color of an element.

Try it

Syntax

/* Keyword values */ background-color: red; background-color: indigo; /* Hexadecimal value */ background-color: #bbff00; /* Fully opaque */ background-color: #bf0; /* Fully opaque shorthand */ background-color: #11ffee00; /* Fully transparent */ background-color: #1fe0; /* Fully transparent shorthand */ background-color: #11ffeeff; /* Fully opaque */ background-color: #1fef; /* Fully opaque shorthand */ /* RGB value */ background-color: rgb(255 255 128); /* Fully opaque */ background-color: rgb(117 190 218 / 0.5); /* 50% transparent */ /* HSL value */ background-color: hsl(50 33% 25%); /* Fully opaque */ background-color: hsl(50 33% 25% / 0.75); /* 75% opaque, i.e. 25% transparent */ /* Special keyword values */ background-color: currentcolor; background-color: transparent; /* Global values */ background-color: inherit; background-color: initial; background-color: revert; background-color: revert-layer; background-color: unset; 

The background-color property is specified as a single value.

Values

The uniform color of the background. It is rendered behind any background-image that is specified, although the color will still be visible through any transparency in the image.

Accessibility concerns

It is important to ensure that the contrast ratio between the background color and the color of the text placed over it is high enough that people experiencing low vision conditions will be able to read the content of the page.

Color contrast ratio is determined by comparing the luminance of the text and background color values. In order to meet current Web Content Accessibility Guidelines (WCAG), a ratio of 4.5:1 is required for text content and 3:1 for larger text such as headings. Large text is defined as 18.66px and bold or larger, or 24px or larger.

Formal definition

Formal syntax

Examples

HTML

div class="exampleone">Lorem ipsum dolor sit amet, consectetuerdiv> div class="exampletwo">Lorem ipsum dolor sit amet, consectetuerdiv> div class="examplethree">Lorem ipsum dolor sit amet, consectetuerdiv> 

CSS

.exampleone  background-color: transparent; > .exampletwo  background-color: rgb(153, 102, 153); color: rgb(255, 255, 204); > .examplethree  background-color: #777799; color: #ffffff; > 

Result

Specifications

Browser compatibility

BCD tables only load in the browser

See also

Found a content problem with this page?

This page was last modified on Jul 18, 2023 by MDN contributors.

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background

The background shorthand CSS property sets all background style properties at once, such as color, image, origin and size, or repeat method. Component properties not set in the background shorthand property value declaration are set to their default values.

Try it

Constituent properties

This property is a shorthand for the following CSS properties:

Syntax

/* Using a */ background: green; /* Using a and */ background: url("test.jpg") repeat-y; /* Using a and */ background: border-box red; /* A single image, centered and scaled */ background: no-repeat center/80% url("../img/image.png"); /* Global values */ background: inherit; background: initial; background: revert; background: revert-layer; background: unset; 

The background property is specified as one or more background layers, separated by commas.

The syntax of each layer is as follows:

• Each layer may include zero or one occurrences of any of the following values:
  • The value may only be included immediately after , separated with the ‘/’ character, like this: » center/80% «.
  • The value may be included zero, one, or two times. If included once, it sets both background-origin and background-clip . If it is included twice, the first occurrence sets background-origin , and the second sets background-clip .
  • The value may only be included in the last layer specified.

  Values

  See background-clip and background-origin . Default: border-box and padding-box respectively.

  See background-color . Default: transparent .

  The following three lines of CSS are equivalent:

  background: none; background: transparent; background: repeat scroll 0% 0% / auto padding-box border-box none transparent; 

  Accessibility concerns

  Browsers do not provide any special information on background images to assistive technology. This is important primarily for screen readers, as a screen reader will not announce its presence and therefore convey nothing to its users. If the image contains information critical to understanding the page’s overall purpose, it is better to describe it semantically in the document.

  Formal definition

  • background-image : none
  • background-position : 0% 0%
  • background-size : auto auto
  • background-repeat : repeat
  • background-origin : padding-box
  • background-clip : border-box
  • background-attachment : scroll
  • background-color : transparent
  • background-position : refer to the size of the background positioning area minus size of background image; size refers to the width for horizontal offsets and to the height for vertical offsets
  • background-size : relative to the background positioning area
  • background-image : as specified, but with url() values made absolute
  • background-position : as each of the properties of the shorthand:
    • background-position-x : A list, each item consisting of: an offset given as a combination of an absolute length and a percentage, plus an origin keyword
    • background-position-y : A list, each item consisting of: an offset given as a combination of an absolute length and a percentage, plus an origin keyword
    • background-color : a color
    • background-image : discrete
    • background-clip : a repeatable list of
    • background-position : a repeatable list of
    • background-size : a repeatable list of
    • background-repeat : discrete
    • background-attachment : discrete

    Formal syntax

    background =
    [ # , ]?

    =
    ||
    [ / ]? ||
    ||
    ||
    ||
    

    =
    ||
    ||
    [ / ]? ||
    ||
    ||
    ||
    

    =
    |
    none

    =
    [ left | center | right | top | bottom | ] |
    [ left | center | right | ] [ top | center | bottom | ] |
    [ center | [ left | right ] ? ] && [ center | [ top | bottom ] ? ]

    =
    [ | auto ] |
    cover |
    contain

    =
    repeat-x |
    repeat-y |
    [ repeat | space | round | no-repeat ]

    =
    scroll |
    fixed |
    local

    =
    border-box |
    padding-box |
    content-box

    =
    |

    =
    |

    =
    url( * ) |
    src( * )

    Examples

    Setting backgrounds with color keywords and images

    HTML

    p class="topbanner"> Starry skybr /> Twinkle twinklebr /> Starry sky p> p class="warning">Here is a paragraphp> p>p> 

    CSS

    .warning  background: pink; > .topbanner  background: url("starsolid.gif") #99f repeat-y fixed; > 

    Result

    Specifications

    Browser compatibility

    BCD tables only load in the browser

    See also

    Found a content problem with this page?

    This page was last modified on Jul 18, 2023 by MDN contributors.

    Your blueprint for a better internet.

    MDN

    Support

    Our communities

    Developers

    Visit Mozilla Corporation’s not-for-profit parent, the Mozilla Foundation.
    Portions of this content are ©1998– 2023 by individual mozilla.org contributors. Content available under a Creative Commons license.

    Источник

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