Color confusion

[dgbustos]

When I run gvim file.Rmd, vim complains:

Error detected while processing /nix/store/ibcbbmsln9vhzsz9bd6psnhh8ida523s-vim-full-9.1.1566/share/vim/vimrc[2]../nix/store/ibcbbmsln9vhzsz9bd6psnhh8ida523s-vim-full-9.1.1566/share/vim/vim91/syntax/syntax.vim[44]..BufRead Autocommands for "*.Rmd"..FileType Autocommands for "*"..Syntax Autocommands for "*"..function <SNR>3_SynSet[25]..script /nix/store/ibcbbmsln9vhzsz9bd6psnhh8ida523s-vim-full-9.1.1566/share/vim/vim91/syntax/rmd.vim[41]../nix/store/ibcbbmsln9vhzsz9bd6psnhh8ida523s-vim-full-9.1.1566/share/vim/vim91/syntax/pandoc.vim[702]..function <SNR>10_SetupPandocHighlights:
line  111:
E254: Cannot allocate color 1
line  112:
E254: Cannot allocate color 1
line  111:
E254: Cannot allocate color 1
line  112:
E254: Cannot allocate color 1

E254: Cannot allocate color 1
E254: Cannot allocate color 1

With some debugging statements I determined that synIDattr() at

vim-pandoc-syntax/syntax/pandoc.vim

Line 685 in ea3fc41

let s:tmp_val = synIDattr(synIDtrans(hlID('String')), s:i)

is returning 1 instead of Magenta, which is what it returns when I run echo synIDattr(synIDtrans(hlID('String')), 'fg') after the editor is running.

With more debugging statements I determined that when that code is running, term is set to xterm-256color even though has('gui_running') returns 1.

Changing the referenced code to

              let s:tmp_ui =  has('gui_running') || (has('termguicolors') && &termguicolors) ? 'gui' : 'cterm'
              let s:tmp_val = synIDattr(synIDtrans(hlID('String')), s:i, s:tmp_ui)

seems to fix it.