UpdateColors function (wingdi.h)

Article
10/13/2021

The UpdateColors function updates the client area of the specified device context by remapping the current colors in the client area to the currently realized logical palette.

Syntax

BOOL UpdateColors(
  [in] HDC hdc
);

Parameters

[in] hdc

A handle to the device context.

Return value

If the function succeeds, the return value is nonzero.

If the function fails, the return value is zero.

Remarks

An application can determine whether a device supports palette operations by calling the GetDeviceCaps function and specifying the RASTERCAPS constant.

An inactive window with a realized logical palette may call UpdateColors as an alternative to redrawing its client area when the system palette changes.

The UpdateColors function typically updates a client area faster than redrawing the area. However, because UpdateColors performs the color translation based on the color of each pixel before the system palette changed, each call to this function results in the loss of some color accuracy.

This function must be called soon after a WM_PALETTECHANGED message is received.

Requirements

Requirement	Value
Minimum supported client	Windows 2000 Professional [desktop apps only]
Minimum supported server	Windows 2000 Server [desktop apps only]
Target Platform	Windows
Header	wingdi.h (include Windows.h)
Library	Gdi32.lib
DLL	Gdi32.dll