Error(s) in re-building vignettes:
--- re-building 'svars.Rnw' using Sweave
Warning in system(paste(shQuote(texi2dvi), if (quiet) "--quiet" else "",  :
  running command '"C:\PROGRA~1\MiKTeX\miktex\bin\x64\texify.exe" --quiet --pdf "svars.tex" --max-iterations=20 -I "C:/r_packages/rinst/share/texmf/tex/latex" -I "C:/r_packages/rinst/share/texmf/bibtex/bst"' had status 1
Error: processing vignette 'svars.Rnw' failed with diagnostics:
running 'texi2dvi' on 'svars.tex' failed

LaTeX errors:
tex:105: Package xcolor Error: Undefined color `Red'.

See the xcolor package documentation for explanation.
Type  H <return>  for immediate help.
 ...                                              
tex:139: Package xcolor Error: Undefined color `Blue'.

See the xcolor package documentation for explanation.
Type  H <return>  for immediate help.
 ...                                              
tex:269: Package xcolor Error: Undefined color `Blue'.

See the xcolor package documentation for explanation.
Type  H <return>  for immediate help.
 ...                                              
tex:311: Package xcolor Error: Undefined color `Blue'.

See the xcolor package documentation for explanation.
Type  H <return>  for immediate help.
 ...                                              
tex:421: Package xcolor Error: Undefined color `Blue'.

See the xcolor package documentation for explanation.
Type  H <return>  for immediate help.
 ...                                              
tex:658: Package xcolor Error: Undefined color `Blue'.

See the xcolor package documentation for explanation.
Type  H <return>  for immediate help.
 ...                                              
tex:924: Package xcolor Error: Undefined color `Blue'.

See the xcolor package documentation for explanation.
Type  H <return>  for immediate help.
 ...                                              
tex:1015: Package xcolor Error: Undefined color `Red'.

See the xcolor package documentation for explanation.
Type  H <return>  for immediate help.
 ...                                              

--- failed re-building 'svars.Rnw'

SUMMARY: processing the following file failed:
  'svars.Rnw'

Error: Vignette re-building failed.
Execution halted