While you could certainly do the colors in an OSM template, it would not be the same. All of the labels were placed by hand, which would not be doable in OSM. H

While you could certainly do the colors in an OSM template, it would not be the same. All of the labels were placed by hand, which would not be doable in OSM. He also stacked together forest layers as well as an elevation hillshade to make it pop like it does, which are raster layers and not available in the vector OSM.