Outside cat / feral cats have had massive negative impacts on bird and small mammal populations. Particularly in areas where they fill an ecological niche that the wildlife hasn’t adapted to due to none of the local fauna being in that niche. Hawaii and Australia in particular have this problem.
Theoretically you’re using actual colors taken from a (or several) environments that you intend to be in. As opposed to a few colors picked by an artist because the artist thought they’d be the colors in those environments.
As for the squares I think it was just an easy way to formulate a pattern digitally. Plus it seemed futuristic at the time.
Other commenter touched on one definition so I’ll explain the other.
Take a bunch of pictures of the woods, put them in a computer and have it tell you the most common colors to generate the a pattern of the most commonly found colors. Boom digital woodland camo.