Note to myself: 1. File => Open 2. Image => Mode => Grayscale 3. Edit => Copy 4. Edit => Undo 5. Layer => New => Transparency => ok 6. Edit => Paste 7. Layer => Anchor Layer 8. Layer => Mask => Add Layer Mask => White (full opacitiy) => Add 9. Now use [...]
Sometimes when working with an image you want to make a certain color transparent. When working with a gif file this would make a round circle look round on any color background. This is actually very simple once you do it once. Finding the information for this took me a while so I thought I would pass it on to anyone that was interested.
1. Open the image in gimp