cobalt.nvim: A Lua repository from wurli

cobalt.nvim

This is a work in progress port of the classic blue theme from TextMate. There are many great themes for Neovim out there, but I've not yet found one as easy on the eyes as this.

Features

Extensive support for TreeSitter syntax highlighting, and many popular plugins
Compilation to lua byte code for super fast startup times

Installation/usage:

Download with your favorite package manager:

lazy.nvim:

 {
     "wurli/cobalt.nvim"
     config = function()
         vim.cmd[[colorscheme cobalt]]
     end
 }

use "wurli/cobalt.nvim"
vim.cmd[[colorscheme cobalt]]

Requirements

neovim latest
truecolor terminal support
undercurl terminal support (optional)

Configuration

There is no need to call setup if you are ok with the defaults.

-- Default options:
require('cobalt').setup({
    compile = false,             -- enable compiling the colorscheme
    undercurl = true,            -- enable undercurls
    commentStyle = { italic = true },
    functionStyle = {},
    keywordStyle = { italic = true},
    statementStyle = { bold = true },
    typeStyle = {},
    transparent = false,         -- do not set background color
    dimInactive = false,         -- dim inactive window `:h hl-NormalNC`
    terminalColors = true,       -- define vim.g.terminal_color_{0,17}
    colors = {                   -- add/modify theme and palette colors
        palette = {},
        theme = { classic = {}, lotus = {}, dragon = {}, all = {} },
    },
    overrides = function(colors) -- add/modify highlights
        return {}
    end,
    theme = "classic",           -- Load "wave" theme when 'background' option is not set
    background = {               -- map the value of 'background' option to a theme
        dark = "classic",        -- try "dragon" !
        light = "lotus"
    },
})

-- setup must be called before loading
vim.cmd("colorscheme cobalt")

NOTE 1: If you enable compilation, make sure to run :CobaltCompile command every time you make changes to your config.

" 1. Modify your config
" 2. Restart nvim
" 3. Run this command:
:CobaltCompile

NOTE 2: Cobalt adjusts to the value of some options. Make sure that the options 'laststatus' and 'cmdheight' are set before calling setup.

Customization

You can conveniently add/modify hlgroups using the config.overrides option. Supported keywords are the same for :h nvim_set_hl {val} parameter.

require('cobalt').setup({
    ...,
    overrides = function(colors)
        return {
            -- Assign a static color to strings
            String = { fg = colors.palette.carpYellow, italic = true },
            -- theme colors will update dynamically when you change theme!
            SomePluginHl = { fg = colors.theme.syn.type, bold = true },
        }
    end,
    ...
})

Transparent Floating Windows

This will make floating windows look nicer with default borders.

overrides = function(colors)
    local theme = colors.theme
    return {
        NormalFloat = { bg = "none" },
        FloatBorder = { bg = "none" },
        FloatTitle = { bg = "none" },

        -- Save an hlgroup with dark background and dimmed foreground
        -- so that you can use it where your still want darker windows.
        -- E.g.: autocmd TermOpen * setlocal winhighlight=Normal:NormalDark
        NormalDark = { fg = theme.ui.fg_dim, bg = theme.ui.bg_m3 },

        -- Popular plugins that open floats will link to NormalFloat by default;
        -- set their background accordingly if you wish to keep them dark and borderless
        LazyNormal = { bg = theme.ui.bg_m3, fg = theme.ui.fg_dim },
        MasonNormal = { bg = theme.ui.bg_m3, fg = theme.ui.fg_dim },
    }
end,

If you'd like to keep the floating windows darker, but you're unhappy with how borders are rendered, consider using characters that are drawn at the edges of the box:

{ "🭽", "▔", "🭾", "▕", "🭿", "▁", "🭼", "▏" }

Borderless Telescope

Block-like modern Telescope UI

overrides = function(colors)
    local theme = colors.theme
    return {
        TelescopeTitle = { fg = theme.ui.special, bold = true },
        TelescopePromptNormal = { bg = theme.ui.bg_p1 },
        TelescopePromptBorder = { fg = theme.ui.bg_p1, bg = theme.ui.bg_p1 },
        TelescopeResultsNormal = { fg = theme.ui.fg_dim, bg = theme.ui.bg_m1 },
        TelescopeResultsBorder = { fg = theme.ui.bg_m1, bg = theme.ui.bg_m1 },
        TelescopePreviewNormal = { bg = theme.ui.bg_dim },
        TelescopePreviewBorder = { bg = theme.ui.bg_dim, fg = theme.ui.bg_dim },
    }
end,

Dark completion (popup) menu

More uniform colors for the popup menu.

overrides = function(colors)
    local theme = colors.theme
    return {
        Pmenu = { fg = theme.ui.shade0, bg = theme.ui.bg_p1 },  -- add `blend = vim.o.pumblend` to enable transparency
        PmenuSel = { fg = "NONE", bg = theme.ui.bg_p2 },
        PmenuSbar = { bg = theme.ui.bg_m1 },
        PmenuThumb = { bg = theme.ui.bg_p2 },
    }
end,

Integration

Get palette and theme colors

-- Get the colors for the current theme
local colors = require("cobalt.colors").setup()
local palette_colors = colors.palette
local theme_colors = colors.theme

-- Get the colors for a specific theme
local classic_colors = require("cobalt.colors").setup({ theme = 'wave' })

Terminal integration

The following example provides a snippet to automatically change the theme for the Kitty terminal emulator.

vim.api.nvim_create_autocmd("ColorScheme", {
    pattern = "cobalt",
    callback = function()
        if vim.o.background == "light" then
            vim.fn.system("kitty +kitten themes Cobalt_light")
        elseif vim.o.background == "dark" then
            vim.fn.system("kitty +kitten themes Cobalt_dragon")
        else
            vim.fn.system("kitty +kitten themes Cobalt")
        end
    end,
})

Acknowledgements

The implementation of this plugin is based on the Kanagawa theme by Tommaso Laurenzi.