tmux, vim: enable true color support properly

.tmux.conf

@@ -5,6 +5,9 @@ set -g @plugin 'tmux-plugins/tmux-prefix-highlight'
 set -g @plugin 'odedlaz/tmux-onedark-theme'
 set -g @onedark_date_format "%d.%m.%y"
 
+set -g default-terminal "tmux-256color"
+set -ga terminal-overrides ",alacritty:Tc,*256col*:Tc"
+
 # Scroll History
 set -g history-limit 50000
 

.vimrc

@@ -31,23 +31,17 @@ set listchars=tab:>-,eol:$,trail:.,extends:#
 
 packadd! onedark.vim
 
-
-"Use 24-bit (true-color) mode in Vim/Neovim when outside tmux.
-"If you're using tmux version 2.2 or later, you can remove the outermost $TMUX check and use tmux's 24-bit color support
-"(see < http://sunaku.github.io/tmux-24bit-color.html#usage > for more information.)
-if (empty($TMUX))
-  if (has("nvim"))
-    "For Neovim 0.1.3 and 0.1.4 < https://github.com/neovim/neovim/pull/2198 >
-    let $NVIM_TUI_ENABLE_TRUE_COLOR=1
-  endif
-  "For Neovim > 0.1.5 and Vim > patch 7.4.1799 < https://github.com/vim/vim/commit/61be73bb0f965a895bfb064ea3e55476ac175162 >
-  "Based on Vim patch 7.4.1770 (`guicolors` option) < https://github.com/vim/vim/commit/8a633e3427b47286869aa4b96f2bfc1fe65b25cd >
-  " < https://github.com/neovim/neovim/wiki/Following-HEAD#20160511 >
-  if (has("termguicolors"))
-    set termguicolors
-    let &t_8f = "\<Esc>[38;2;%lu;%lu;%lum"
-    let &t_8b = "\<Esc>[48;2;%lu;%lu;%lum"
-  endif
+if (has("nvim"))
+  "For Neovim 0.1.3 and 0.1.4 < https://github.com/neovim/neovim/pull/2198 >
+  let $NVIM_TUI_ENABLE_TRUE_COLOR=1
+endif
+"For Neovim > 0.1.5 and Vim > patch 7.4.1799 < https://github.com/vim/vim/commit/61be73bb0f965a895bfb064ea3e55476ac175162 >
+"Based on Vim patch 7.4.1770 (`guicolors` option) < https://github.com/vim/vim/commit/8a633e3427b47286869aa4b96f2bfc1fe65b25cd >
+" < https://github.com/neovim/neovim/wiki/Following-HEAD#20160511 >
+if (has("termguicolors"))
+  set termguicolors
+  let &t_8f = "\<Esc>[38;2;%lu;%lu;%lum"
+  let &t_8b = "\<Esc>[48;2;%lu;%lu;%lum"
 endif
 
 syntax on