How to change the color of an icon with Gimp.

A while ago I wanted to change colored images and icons to black - white using gimp.

I was using fedora(operating system).Since it comes with fedora distribution.The installation is as easy as:

$ sudo dnf install gimp

Find an original icon;i mean the free ones or you can buy still.Check License.Then convert it to black and white.

Here is Gatsby Icon

We want the icon to look like the one below.

Step 1: Open the image in Gimp

Here is how it looks like in Gimp

Step 2: Add an new Layer

Add a new layer to the image by selecting Layer > New Layer.Call it color.Fill this layer with the Black color.The color we want to change our icon to. In my case,it is the Foreground Color,so I choose Foreground color. Make sure it’s on top of the Background layer as shown below.

Hide this new layer so we can work on the Background layer by clicking on the eye button just to the left of the layer thumbnail.

Step 3: Manipulate the colors

Select the Background layer.Desaturate the image by selecting Colors > Desaturate.Choose Lightness for the dialog that pops up.

Your image should look greyish like below image.

Now, invert the image by selecting Colors > Invert

Step 4: Adjust Curves

Since in my case,I know my Background Color is white.I can adjust the curves as shown below. And get the below image.

To adjust the curves select Colors > Curves.

Foreground and Background colors are always displayed in gimp as shown below

Step 5: Flip Black and White Color

Now Select Colors > Invert to flip the black and white color.

You should see the resultant image below

The red arrow in the screenshot shows your steps in summary.

Voila! You are done.

6: Export your new icon

You can export your visible icon by Selecting File > Export as ...

Give it a new name so that you don’t overwrite the original one in case you missed a step and need to follow the process again.

Reference

The web article describing the process much better.