Slate for Home Assistant

Slate is a dark theme that does one thing: charcoal cards on a slightly darker background, a steel blue for switches, sliders and anything active, and a mustard yellow for the secondary accent. There are no gradients, no translucency and no card borders, so it suits a wall panel that should look like a control surface rather than a phone app. The theme file is under 50 lines, which also makes it the easiest theme on this page to read and tweak if you want your own accent colour.

It comes from Sean Green's shared Home Assistant configuration, one of the setups people copied from in the early Lovelace days, and it is still ticking over: the last commit, in April 2026, moved it onto the current modes format and added an icon colour fix. There are no tagged releases, so check the commit history rather than a releases page. Expect the newer frontend components to fall back to default styling where the theme does not name a variable; the palette is small enough that this is rarely jarring.