I have a gif image that I want to use as a background on a web site, but it's a bit too colourfull and when text is laid over the top of it, there's not enough contrast, so I want to knock it back a little.
I thought I could use a plain white layer in GIMP (v2.10.6) on top of my image and set that white layer to 50% opacity. On the screen, it looks about right, but when I try to export my image, parts of it just turn plain white, and other bits go grey. Same problem if I reverse this and set the original image to 50% opacity over a white background. I can't figure out what I'm doing wrong. I've tried exporting as PNG, GIF, and JPG, but the result is the same for all three.
FYI, I get the same result if I try playing around with lightness and saturation settings instead of the white layer.
Here are some links to illustrate the problem:
- Original image https://drive.google.com/open?id=1iKLFFN39-4MK5iKRuvazVqfHox3c5RFP
- Screen shots of GIMP https://drive.google.com/open?id=10UR1Awqoo-OUJsic8xcaIxqujDRV6lyd
- Exported image https://drive.google.com/open?id=1dkVXDdWr7OD9RnUEolCevHrsktCeQrdz
How do I get the exported image to look like the image in GIMP?