If you share the site URL we can have a look and tell you what images you need to change. Alternatively, there are various tools that can help: Https://webspeedtest.cloudinary.com - image analysis tool that will actually give you optimized images (be aware that Google Sites only accepts JPEGs, PNGs and GIFs) Https://squoosh.app/ - image compressor if you want to manually do it and go with a higher level of... Source: over 3 years ago

I like dithered images and appreciate the author's post. If you don't, but you want your webpages to load fast, look into WebP and AVIF images. Load them opportunistically using the html5 PICTURE tag - no JS required and no worry about old browsers not supporting new formats. Even plain lossless encoding of legacy formats goes a long way. Test your own site for ideas: https://webspeedtest.cloudinary.com. - Source: Hacker News / over 3 years ago

Maybe it will be overkill for flags, but you can try with dithering algorithms, where you can select which color you want to keep: Https://ditherit.com/ Https://github.com/noopkat/floyd-steinberg. Source: over 2 years ago

ImageMagick can do anything, but it's a commandline program. There may be some websites that dither images for you - https://ditherit.com/ is one. (I also wrote a program years ago that is excellent at color reduction and dithering, but it's not currently usable.). Source: over 2 years ago

It’s called dithering. Instead of using many different colors you just choose a few and make the best of it. With using six colors (red, green, blue, yellow, white, black) any color can be matched. You can try it out with this tool: https://ditherit.com/. Source: almost 3 years ago

I used https://pixelartselfie.com/en. I later found https://ditherit.com/ which offers more features so I’ll probably do more works. Source: almost 3 years ago

Check this website: https://ditherit.com/. Source: almost 3 years ago