Change the value of the transparent color

In 24 BPP or less images, you can change the value of the color used for transparency.

How transparency in images is handled by IconWorkshop?

The Alpha Channel transparency is coded in a 8 BPP channel which permits creating smooth and variable transparent areas in images. The simulated transparency is used in images containing 24 BPP or less color depth. For these images, the transparency is coded by using a fixed color. Each pixel that have this exact color will be converted as transparent when the image is loaded in the application. Usually, the color used is a flashy green RGB(0,255,0) or magenta RGB(255,0,255). The problem of this method is that if you use a pixel of that color in your icon image (not the background), it will be converted as transparent. The other issue is the poor quality of the borders (around the icons) because it does not permit smooth transparency. In other words, a pixel is either 100% transparent or 100% opaque, there is no variable transparency. It results in "aliasing" on borders for icons with rounded shapes.

In 32 BPP (RGB/A) images, the transparency is coded in the alpha channel and saved in the image itself.

As we discussed above, for 24 BPP or less color depths the transparency is coded by a specific color. IconWorkshop automatically detect this color and display the icons with a real transparency. You don't see the Gteen or Magenta color as coded in the image. Instead you see the chessboard texture which indicates that this is a transparent zone.

When you save the image, the original color is applied back in the image. Note that during the edition, you can change the transparent color of the image.

Changing the value of the transparent color

1. Choose Color/Set Image Background Color.

2. Select the color using the dialog box. Click OK.

3. The new transparent color has been changed.

REMARK - Once the color has been changed, there is no visual difference in the editor window. The tranparent pixels are still shown as a chessboard texture. The color will be applied when you'll save the image.