Color Models Used by the Color Dialog Box - Win32 Programmer's Reference

Custom Search

Color Models Used by the Color Dialog Box

The custom colors extension of the Color dialog box allows the user to specify a color using RGB or HSL values. However, the CHOOSECOLOR structure uses only RGB values to report the colors created or selected by the user.

RGB Color Model
The RGB model is used to designate colors for displays and other devices that emit light. Valid red, green, and blue values range from 0 through 255, with 0 indicating minimum intensity and 255 indicating maximum intensity. The following illustration shows how the primary colors red, green, and blue can be combined to produce four additional colors. (For display devices, the color black results when the red, green, and blue values are set to 0. In display technology, black is the absence of all colors.)

Following are eight colors and their associated RGB values.

Color	RGB values
Red	255, 0, 0
Green	0, 255, 0
Blue	0, 0, 255
Cyan	0, 255, 255
Magenta	255, 0, 255
Yellow	255, 255, 0
White	255, 255, 255
Black	0, 0, 0

Windows stores internal colors as 32-bit RGB values that have the following hexadecimal form:

0x00bbggrr

The low-order byte contains a value for the relative intensity of red; the second byte contains a value for green; and the third byte contains a value for blue. The high-order byte must be zero.

You can use the RGB macro to get an RGB value based on specified intensities for the red, green, and blue components. Use the GetRValue, GetBValue, and GetGValue macros to extract individual colors from an RGB color value.

HSL Color Model
The Color dialog box provides controls for specifying HSL values. The following illustration shows the color spectrum control and the luminosity slide control that appear in the Color dialog box. The illustration also shows the ranges of values the user can specify with these controls.

In the Color dialog box, the saturation and luminosity values must be in the range 0 through 240, and the hue value must be in the range 0 through 239.

Converting HSL Values to RGB Values
The dialog box procedure provided in COMDLG32.DLL for the Color dialog box contains code that converts HSL values to the corresponding RGB values. Following are several colors and their associated HSL and RGB values.

Color	HSL values	RGB values
Red	(0, 240, 120)	(255, 0, 0)
Yellow	(40, 240, 120)	(255, 255, 0)
Green	(80, 240, 120)	(0, 255, 0)
Cyan	(120, 240, 120)	(0, 255, 255)
Blue	(160, 240, 120)	(0, 0, 255)
Magenta	(200, 240, 120)	(255, 0, 255)
White	(0, 0, 240)	(255, 255, 255)
Black	(0, 0, 0)	(0, 0, 0)

Last news from Greatis Software

    Nostalgia .Net     .Net is powerful, but not all-powerful, so sometimes we need to use Win32 API for our .Net applications. It's simple enough with Platform Invoke if you have Win32 skill, but we do not always have time to dig the ancient documentation, declare the special types that are compatible with Win32, find the values of the Win32's constants and so on. Nostalgia .Net offers several simple-to-use classes, and components that will allow you to forget about the headache of Win32 and just use the power of Win32 in your application the same way as you use the native. Net classes. More »

Recommended software for developers

    Ultimate Pack     Component pack for Delphi and C++ Builder that contains runtime form designer, runtime object inspector, print suite and much more for the very special price. More »

    Form Designer .Net     Unique runtime form design solution that allows to edit any form in .Net WinForms application at runtime with full source codes for only 300 euro! More »

    Print Suite .Net     Print Suite .Net is a set of components for easy printing texts, images and grids from your WinForms applications. Full C# source codes are available More »

    Gradient Controls .Net     Gradient Controls .Net offers controls with gradient background feature. Labels, panels and so on... Full C# source codes are available More »

    Greatis iGrid     iGrid plots drawing grid right over your desktop, so you can use it everywhere, with any drawing application without any special plugins for different graphic editors. More »

All the contacts and projects

Dmitry Vasiliev (just.dmitry)

More Online Helps

Win32 Programmer's Reference
Win32 Multimedia Programmer's Reference
OLE Programmer's Reference
Microsoft Windows Pen API Programmer's Reference
Microsoft Windows Sockets 2 Reference
Microsoft Windows Telephony API (TAPI) Programmer's Reference
Unix Manual Pages

greatis just4fun network