Web colors
Web colors are colors that are used for designing websites. Web designers have multiple ways to set the color of individual elements on their websites. Many colors are already named, so that no knowledge of the decimal or hexadecimal color notation is necessary.
- 2.1 HTML 4/VGA
- 2.2 CSS 3
- 2.3 Manufacturer -specific color names
Color quotes in Style Sheets ( CSS)
Web developers have different ways to write a color in a stylesheet:
RGB color space
Colors of the RGB color space are defined as follows:
P { color: # F00; } / * # Rgb * / p { color: # FF0000; } / * # Rrggbb * / p {color: rgb ( 255, 0, 0); } / * Integer 0 - 255 * / p {color: rgba (64, 0, 0, 0.7); } / * 0.7 = 70 % opacity - specified in CSS 3 * / p {color: rgb ( 100 %, 0 %, 0 %); } / * Entries in percent 0.0% - 100.0 % * / HSL
Colors according to the model of the HSL color space can from CSS 3 are listed as follows:
P {color: hsl (120, 100%, 50 %); } / * Green * / p {color: hsl ( 120, 100 %, 25 %); } / * Dark green * / p {color: hsl ( 120, 100 %, 75 %); } / * Green * / p {color: hsl (120, 50%, 50 %); } / * Pastel green * / p {color: HSLA (120, 100%, 50 %, 0.7); } / * Green with 70 % opacity * / CMYK
From CSS 3 colors can also be specified by the CMYK color model:
Many color values is assigned a name. They can be used as follows:
P {color: navy; / * Dark blue * /} p {color: red; / * Red * /} The assignment of the color values is described below.
Listing with backward compatibility
Since only modern browser rgba, hsl ( a) - and cmyk quotation interpret, web developers need to define a so-called fallback color:
P { color: red; / * Backward compatibility * / color: cmyk (0.0, 0.95, 1, 0.1); / * Used by modern browsers interpret * / } named Colors
There are several standards, the color names to assign the hexadecimal codes. Solassen to the English name in place of the percentage values in the RGB color space to specify. By specifying such names it is without the hexadecimal notation for the developer to choose the color possible after the presentation.
HTML 4/VGA
The dark colors result from an (almost ) halve the red, green and blue values of 0xFF to 0x80 (exception: black and silver).
CSS 3
The CSS 3 specification of the World Wide Web Consortium (W3C ) defines the list of X11, which was standardized for SVG 1.0, 140 following colors:
This can also be written gray instead of gray syllable. Furthermore, aqua and cyan and fuchsia and magenta respectively represent the same color. The list is essentially made up of the 120 colors of the Netscape browser and the 16 VGA colors. Only the color bisque (# FFE4C4 ) and BlanchedAlmond (# FFEBCD ) do not come therefore.
Manufacturer -dependent color names
In addition, the manufacturer of browsers have defined a plurality of color names. In these, however, is no guarantee that all browsers can interpret these color names.
Web-safe colors
A set of colors is commonly referred to as Web-safe color palette. This was developed as a computer usually could only display 256 colors and a palette of colors was needed that did not have to be approximated from the artwork by dithering. Operating systems are using for your own use about 16 to 20 otherwise usable colors, so remained around 236 freely selectable colors. Another consideration was, for each primary color (red, green, and blue) to offer six different colors, so were ( for the three primary colors) 6 × 6 × 6 = 63 = 216 displayable colors chosen. The range was first proposed by Lynda Weinman. By default it was first implemented by Netscape, with the remaining 40 of 256 colors were freely definable. The web-safe colors have no names, ie is determined by the terms of their RGB values in the RGB color space. The RGB values for each color be in hexadecimal 0x00, 0x33, 0x66, 0x99, 0xCC, 0xFF.
Designers are often encouraged to use the 216 web-safe colors in their websites. The web-safe colors were developed in the mid 1990s, were as graphics cards with 8 bit color depth of the usual standard. Due to the proliferation of video cards, which can represent 24 -bit color or better, the mandatory use of the web-safe palette of colors lost in the last few years. For web pages for a wide range of users (portals, search engines, news) with a wide variety of monitors and computer types the application of Web-safe colors is today and probably no alternative in the future. The graphically rich user can select a sufficient match the computed color values programmed with the displayed image results by calibrating the monitor used to display the web color with purely visual means approximately or between the offered by some manufacturers alternatives to the standard representation. The expectations of a true color rendition still can not be high in commercially available monitors ( Twisted Nematic). Manufacturer peculiarities, viewing angle and ambient light, the display greatly affect and contribute to the fact that color differences of neighboring colors in the color space are mostly not or hardly recognizable.