Credit: u/JG_Online and u/UltraWorlds. This is the comment on the original post from reddit:

Languages are categorized by linguistic families by colours.

So Spanish and Portugese (both being Romance) are redish shades, similarly other linguistic groups share similar shades indicating these are closely related languages. (this scheme breaks down quite a bit with so many languages but generally it checks out here, if you have some linguistic background)

The map does not include labels as to no obscure the detail we put into it, so I guess this map is mainly for ppl who already have some linguistic landscape knowledge.

Area’s which have between 30 to 70% majority are shown as striped.

Area’s with a population density below 1p/km2 are shown as sparsely populated. This does not mean no one lives there but rather that a single immigrant family can add Korean to the Sahara desert, which is not what this map is about.

Languages with less than 20,000 speakers in a populated area are not shown. (This mainly to exclude the native american languages that are overwhelmingly outpopulated in states such as NY or CA)

Linguistic Isolates are shown in various grey shades.

The friend who helped me with this map is u/UltraWorlds