Strings with 256 are replaced by <t_Co>

[rtucek]

This is kinda annoying and Google is giving me wrong answers.

Whenever I paste text from the clipboard into vim, it replaces all occurrences of 256 with <t_Co>.

I use vim in gnome-terminal
vim version is

:version
VIM - Vi IMproved 7.4 (2013 Aug 10, compiled Nov 24 2016 16:44:48)
Included patches: 1-1689
Extra patches: 8.0.0056
Modified by pkg-vim-maintainers@lists.alioth.debian.org
Compiled by pkg-vim-maintainers@lists.alioth.debian.org
Huge version without GUI.  Features included (+) or not (-):
+acl             -clipboard       +dialog_con      +file_in_path    +job             +menu            -mouse_sysmouse  +persistent_undo +scrollbind      -tcl             +visual          -xim
+arabic          +cmdline_compl   +diff            +find_in_path    +jumplist        +mksession       +mouse_urxvt     +postscript      +signs           +terminfo        +visualextra     -xsmp
+autocmd         +cmdline_hist    +digraphs        +float           +keymap          +modify_fname    +mouse_xterm     +printer         +smartindent     +termresponse    +viminfo         -xterm_clipboard
-balloon_eval    +cmdline_info    -dnd             +folding         +langmap         +mouse           +multi_byte      +profile         +startuptime     +textobjects     +vreplace        -xterm_save
-browse          +comments        -ebcdic          -footer          +libcall         -mouseshape      +multi_lang      -python          +statusline      +timers          +wildignore      -xpm
++builtin_terms  +conceal         +emacs_tags      +fork()          +linebreak       +mouse_dec       -mzscheme        +python3         -sun_workshop    +title           +wildmenu
+byte_offset     +cryptv          +eval            +gettext         +lispindent      +mouse_gpm       +netbeans_intg   +quickfix        +syntax          -toolbar         +windows
+channel         +cscope          +ex_extra        -hangul_input    +listcmds        -mouse_jsbterm   +packages        +reltime         +tag_binary      +user_commands   +writebackup
+cindent         +cursorbind      +extra_search    +iconv           +localmap        +mouse_netterm   +path_extra      +rightleft       +tag_old_static  +vertsplit       -X11
-clientserver    +cursorshape     +farsi           +insert_expand   -lua             +mouse_sgr       -perl            -ruby            -tag_any_white   +virtualedit     -xfontset
   system vimrc file: "$VIM/vimrc"
     user vimrc file: "$HOME/.vimrc"
 2nd user vimrc file: "~/.vim/vimrc"
      user exrc file: "$HOME/.exrc"
  fall-back for $VIM: "/usr/share/vim"
Compilation: gcc -c -I. -Iproto -DHAVE_CONFIG_H   -Wdate-time  -g -O2 -fPIE -fstack-protector-strong -Wformat -Werror=format-security -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=1
Linking: gcc   -Wl,-Bsymbolic-functions -fPIE -pie -Wl,-z,relro -Wl,-z,now -Wl,--as-needed -o vim        -lm -ltinfo -lnsl  -lselinux  -lacl -lattr -lgpm -ldl     -L/usr/lib/python3.5/config-3.5m-x86_64-l
inux-gnu -lpython3.5m -lpthread -ldl -lutil -lm

My vim config is

"-----GENERAL-----
"The default leader is a backslash, but we use ','
let mapleader = ','

"Fix backsapce key"
set backspace=indent,eol,start

"Set language for spell check
setlocal spell spelllang=en_us

"Fixing tabs and indentation
set tabstop=4
set expandtab
set shiftwidth=4
set autoindent
set smartindent
set cindent

"Refresh buffer
set autoread

"-----VUNDLE-----
so ~/.vim/plugins.vim

"-----VISUAL-----
"Syntax highlighting
syntax enable

"From https://github.com/gosukiwi/vim-atom-dark
colorscheme atom-dark-256
set t_Co=256

"Force 256 colors in terminal
set t_CO=256

"Show line numbers
set number

"Show column length
set ruler
"Show visual mark at the 80th character
set colorcolumn=80
highlight OverLength ctermbg=red ctermfg=white guibg=#592929
match OverLength /\%81v.\+/

"-----MAPPINGS-----
"Quick edit .vimrc
nmap <Leader>ev :tabedit $MYVIMRC<cr>

"Removes the highlighted search results
nmap <Leader><space> :nohlsearch<cr>
nmap <Leader>d :NERDTreeToggle<cr>

"-----SPLIT-MANAGEMENT-----
nmap <C-J> <C-W><C-J>
nmap <C-K> <C-W><C-K>
nmap <C-H> <C-W><C-H>
nmap <C-L> <C-W><C-L>

"-----CtrlP-Binding-----
nmap <C-r> :CtrlPBufTag<cr>

"-----AUTO-COMMANDS-----
augroup autosourcing
	autocmd!
	"Auto sourcing the .vimrc file on safe
	autocmd BufWritePost .vimrc source %
augroup END

"-----SEARCHING-----
set hlsearch
set incsearch

[brammool]

Try dropping these lines:

"Force 256 colors in terminal
set t_CO=256

The name is t_Co, not t_CO.

[rtucek]

@brammool Thank you so much - this drove me crazy.