The Blend filter is included with the GIMP package and it can make a color transition animation quickly and easily. This is a basic tutorial to get you started with using the filter. Create other variations after you get comfortable doing Blend animations.
First create the basic image. I used the KR Scribble Heart font for this one. You can get it
here.
Start with a new, blank image. You can use a transparent background or fill it with the color of the background where you will be displaying the image. I chose white for the background here. The Blend filter uses the Background layer for the background of your finished animation.
Keep in mind, you MUST have a background layer, whether transparent or filled with color. If you don't the Blend filter will use the bottom layer for the background and you will lose one of your color transition images.
Use black for the foreground color and use the
Text tool to type your text. After you have the first layer, duplicate it two times so that you have three text layers. You can see the layers in the image below.
Right-click the bottom text layer (not the Background layer) and choose Alpha to Selection in the drop down list, then Select > Shrink > and shrink the selection by 2 pixels. Fill the selection with the color of your choice - you can also use patterns or gradients, go to the next text layer and fill with another color, do the top text layer with another color.
Turn off the selection by using Ctrl + Shift + A, or Select > None.
Now you are ready to use the blend tool. You may want to crop your image first - click a text layer with the mouse, Image > Autocrop.
Filters > Animation > Blend
In the Blend filter dialog, the default is 3 Intermediate frames and I used the default for this demonstration. Keep in mind, more Intermediate frames makes more blending frames which makes the transitions longer and smoother. It also makes your file size larger.
Here is the finished animation. I used 160milliseconds per frame when I saved the animation rather than the default 100ms.
Here is a variation of using the Blend filter. Download the fall leaves brushes attached below.