A HyperText Markup Language (HTML) color picker generally is a program that allows a user to review all the colors available in a computer display and then select specific colors. This is sometimes required because many computer monitors are capable of displaying millions of colors and some web designers might need to match exact colors from a logo, photograph or other real-world source. Another reason why an HTML color picker can be necessary is that the most common way of representing a color in an HTML document or a cascading style sheet (CSS) is in the form of a hexadecimal number. A color picker makes finding the exact hexadecimal value of a color easier and may provide other convenient functions.
The most basic type of HTML color picker is usually represented as a bar of colors next to a larger block of colors. The idea is to select a general color from the bar, such as yellow, and then all of the gradations of that color will appear in the larger block. Selecting a color from the field of specific gradations triggers the hexadecimal value of that exact color to be displayed, sometimes in the form of usable HTML code. A slightly more advanced HTML color picker might have named colors recorded and be able to provide the names of colors that match the hexadecimal sequence, making the HTML code easier to read. This type of basic HTML color picker can be found as a utility on the Internet and can be downloaded as a standalone application.
An HTML color picker that is a standalone application usually has more features than an online version. One useful feature is the ability to isolate a color at a point outside the program itself, such as somewhere on the desktop or in another window. This can be used to find the hexadecimal code for colors that could be in a digital image or even another website without having to resort to using screen captures or separate paint programs.
Other features that an HTML color picker can implement include recording entire color schemes so they can either be referenced repeatedly or saved and exported for different design projects. Some HTML color pickers can use vector mathematics and other algorithms to actually generate entire color schemes that can be used on a website. This can mean finding the mathematically complementary or analogical colors for a given selection, sometimes providing some direction during the design process.