Hades

Hades is a minimal colorscheme based on Apprentice. It comes in a light and a dark variant based on vim.opt.background. You can use the following in your config to switch theme depending on the time of day:

local hr = tonumber(os.date('%H', os.time()))
if hr > 6 and hr < 21 then -- day between 6am and 9pm
  vim.opt.background = 'light'
else -- night
  vim.opt.background = 'dark'
end

Screenshot

Design

The theme simply uses vim.api.nvim_set_hl to set highlight colors and does not aim to provide any customisability. I started with setting all syntax highlights to white, adding color only when I feel it is needed. The colors are chosen to be distinguishable from each other and to provide reasonable contrast.