winapi - Vista/7: How to get glass color?

Question

How do you use DwmGetColorizationColor?

The documentation says it returns two values:

• a 32-bit 0xAARRGGBB containing the color used for glass composition
• a boolean parameter that is true "if the color is an opaque blend" (whatever that means)

Here's a color that i like, a nice puke green:

You can notice the color is greeny, and the translucent title bar (against a white background) shows the snot color very clearly:

i try to get the color from Windows:

DwmGetColorizationColor(dwCcolorization, bIsOpaqueBlend);

And i get

dwColorization: 0x0D0A0F04
bIsOpaqueBlend: false

According to the documentation this value is of the format AARRGGBB, and so contains:

AA: 0x0D (13)
RR: 0x0A (10)
GG: 0x0F (15)
BB: 0x04 (4)

This supposedly means that the color is (10, 15, 4), with an opacity of ~5.1%.

But if you actually look at this RGB value, it's nowhere near my desired snot green. Here is

• (10, 15, 4) with zero opacity (the original color), and
• (10,15,4) with 5% opacity against a white/checkerboard background:

Rather than being Lime green, DwmGetColorizationColor returns an almost fully transparent black.

So the question is: How to get glass color in Windows Vista/7?

i tried using DwmGetColorizationColor, but that doesn't work very well.

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A person with same problem, but a nicer shiny picture to attract you squirrels:

So, it boils down to – DwmGetColorizationColor is completely unusable for applications attempting to apply the current color onto an opaque surface.

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i love this guy's screenshots much better than mine. Using his screenshots as a template, i made up a few more sparklies:

For the last two screenshots, the alpha blended chip is a true partially transparent PNG, blending to your browser's background. Cool! (i'm such a geek)

Edit 2: Had to arrange them in rainbow color. (i'm such a geek)

Edit 3: Well now i of course have to add Yellow.

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Undocumented/Unsupported/Fragile Workarounds

There is an undocumented export from DwmApi.dll at entry point 137, which we'll call DwmGetColorizationParameters:

HRESULT GetColorizationParameters_Undocumented(out DWMCOLORIZATIONPARAMS params);

struct DWMCOLORIZATIONPARAMS
{
   public UInt32 ColorizationColor;
   public UInt32 ColorizationAfterglow;
   public UInt32 ColorizationColorBalance;
   public UInt32 ColorizationAfterglowBalance;
   public UInt32 ColorizationBlurBalance;
   public UInt32 ColorizationGlassReflectionIntensity;
   public UInt32 ColorizationOpaqueBlend;
}

We're interested in the first parameter: ColorizationColor.

We can also read the value out of the registry:

HKEY_CURRENT_USERSoftwareMicrosoftWindowsDWM
    ColorizationColor: REG_DWORD = 0x6614A600

So you pick your poison of creating appcompat issues. You can

• rely on an undocumented API (which is bad, bad, bad, and can go away at any time)
• use an undocumented registry key (which is also bad, and can go away at any time)

See also

• Is there a list of valid parameter combinations for GetThemeColor / Visual Styles API
• How does Windows change Aero Glass color?
• DWM - Colorization Color Handling Using DWMGetColorizationColor
• Retrieving Aero Glass base color for opaque surface rendering

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i've been wanting to ask this question for over a year now. i always knew that it's impossible to answer, and that the only way to get anyone to actually pay attention is to have colorful screenshots; developers are attracted to shiny things. But on the downside it means i had to put all kinds of work into making the lures.

Answer 1

Colorization color != the base color chosen. It's misleading, I know.

But I'm confused. The image you borrowed was from my post entitled "Retrieving Aero Glass base color for opaque surface rendering". Is this not what you want to do? I also indicated in the post the registry location in which all the color information is stored (HKEY_CURRENT_USERSoftwareMicrosoftWindowsDWM) for retrieval purposes.

Edited 8/26

DwmGetColorizationColor (dwmapi.dll) returns the "colorization color", which is a blend of various colors (incl. your selected base color) and shader logic to achieve the overall glass effect.

All the color information you need/want can be found in the registry key noted above. The base color, the colors used in blending, and the resulting colorization color are all there.

(The key above is present on Windows Vista and above.)