Macos – How to change the background color of a transparent desktop image on Mac OS X

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Under Desktop & Screen Saver I have selected to show a PNG image with transparency on my Desktop. It looks like this:

Screenshot

The transparent area shows the exact same color that is listed as the first solid color under Apple -> Solid Colors. I tried changing the solid color to something else, then select the image again, hoping it would remember the last solid color selection. But after selecting an image it always reverts back to showing the blue-ish color as the transparent area of the image. I would very much like to change the background color of the image's transparent area.

How can I change the background color of transparent desktop images? Is it even possible?

Best Answer

Argh. Just after asking the question I figured it out!

First, select either Center or Fit to Screen from the selection above the image thumbnail view. To the right a color selection button will appear.

Now change that color to whatever you want, then set the selection back to Tile or any of the other settings that don't support changing the background color. The selected background color will still be used for the transparent areas of the image.

Related Solutions

How to remove a png file’s background using Paint.NET

The Magic wand is your friend. I could supply you with a completed PNG but I'd rather show you how to do it

enter image description here

Things of note? Use the contiguous not global setting. Play with the tolerances - I went with 70 percent to knock some of the antialising off. I picked a larger area to work on but you can/should just zoom in when working. Having a black background layer is a nice way to check if your cropping is fine.

Windows – How to replace the Desktop background image with a solid color, using PowerShell and registry

Indeed I found two methods. One using CMD-R to run some windows magic, and another by setting the PATH value to null with ('').

However, apparently there is another registry item containing the path in hex encoded form, in HKCU:\Control Panel\Desktop\TranscodedImageCache, that you can see by the rudimentary hex conversion.

# Set the wallpaper PATH to ''
$key = 'HKCU:\Control Panel\Desktop'
Set-ItemProperty -Path $key -Name 'WallPaper' -Value ''

# Re-start windows Explorer:
Stop-Process -ProcessName explorer

# Using `CMD+R` and run : 
shell:::{ED834ED6-4B5A-4bfe-8F11-A626DCB6A921} -Microsoft.Personalization\pageWallpaper

# Getting the "Transcoded" PATH:
$TIC=(Get-ItemProperty 'HKCU:\Control Panel\Desktop' TranscodedImageCache -ErrorAction Stop).TranscodedImageCache
[System.Text.Encoding]::Unicode.GetString($TIC) -replace '(.+)([A-Z]:[0-9a-zA-Z\\])+','$2'

#C:\Windows\Web\Wallpaper\Windows\_img0.jpg

Also related to this answer.

You need to restart windows explorer.exe (use Sysinternal's Process Explorer or PS with: Stop-Process -ProcessName explorer) in order for registry changes to take effect.

UPDATE: 2020-01-09

You don't need to re-start explorer, nor compile anything via PoweShell, ... almost. From THIS blog and this SESU answer, I found a fantastic one-liner:

add-type -typedefinition "using System;`n using System.Runtime.InteropServices;`n public class PInvoke { [DllImport(`"user32.dll`")] public static extern bool SetSysColors(int cElements, int[] lpaElements, int[] lpaRgbValues); }"

# Now to get your desktop to instantly turn purple, run it with:
[PInvoke]::SetSysColors(1, @(1), @(0xAA40C0))
# Or tack it on the end of above for a true one-line experience.

Notes from author: "This doesn't affect the Registry, so if you want the change to stick, you need to also write the new data to Registry yourself."

Best Answer

Related Solutions

How to remove a png file’s background using Paint.NET

Windows – How to replace the Desktop background image with a solid color, using PowerShell and registry

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