This pack only uses 216 colors which are titled "Web Safe".
Here is a Wiki page about them: [Link]
Basically this pack is more like one of those 8bit, old school vibe, packs.
Semi-transparency doesn't exist and some blocks share really similar textures.
It is just interesting to use it while flying around and looking at different builds.
The reason why I made this is because my paint software outputs this format even if I select "256".
So I just decided to use it on all textures, by hand. Originally made ~1 year ago, but it is updated to 1.20.
Btw, it is so large because it makes even smallest textures into ~1.2kb.