a simple, muted stylesheet For tilemill2: that is designed to be used as a base map, using pastels.
Right now, design was only consciously done for zoom levels 13 and higher but it can be extended for lower zoom levels.
See it in action at: https://a.tiles.mapbox.com/v4/skorasaurus.j73ni225/page.html?access_token=pk.eyJ1Ijoic2tvcmFzYXVydXMiLCJhIjoiaEdGTUZWTSJ9.osOC8tWU3bMaNprVNoEu7g#15/41.5040/-81.6829
Based from OSM Bright for TM2;
powered by MapBox vector tiles and TM2.