This question is posted as a requested follow-on from options for appearance of links in hyperref , to clear up some odd behaviour in hyperref.

In the snippet below, the two \usepackage commands both work, but linkcolor=. throws an error when combined with colorlinks=true (error text shown at end of post).




See Figure~\ref{fig}

        \caption{This is an empty figure \label{fig}}

If I use the line


(note the dot), I get error text:

LaTeX Error: Undefined color

and the error comes immediately after the closing brace of \ref{}

The effect I wanted to achieve was to remove boxes around links and leave all links text color except actual URLs, so when I used this command I also had urlcolor=blue in the options, but that was not needed to reproduce the error. But the following line did work, in that all links but URLs were invisible:


Using MiKTeX-pdfTeX 2.9.6959 (1.40.20) (MiKTeX 2.9.6960) on Windows 10

  • 1
    Add \usepackage{xcolor}. – Ulrike Fischer Mar 4 '19 at 23:36
  • Of course you get an error with linkcolor=. as this is setting the colour to ., which is a non-existent colour. SImialrly, with linkcolor= you are remving all colour so the lins are invisible. Doesn't \usepackage[colorlinks=true,linkcolor=black]{hyperref} give what you want? – user30471 Mar 4 '19 at 23:38
  • Thank you for your advice to add xcolor. Perhaps hyperref should be loading it? I did not want to assume text was black. linkcolor=. is supposed to match the current text colour. See the discussion linked in the question for context. linkcolor=. works under some circumstances. The dot on its own is not necessarily an error. – Dr Darren Mar 4 '19 at 23:56

linkcolor=. causes hyperref to issue \color{.}

which produces

LaTeX Error: Undefined color `.'

as there is no colour of that name using the standard color package as loaded by hyperref.

You are possibly thinking of the xcolor package syntax wher . means the current color


works, although specifying coloured links this way seems slightly strange choice rather than just specifying the link border to have width 0.

| improve this answer | |
  • Strange to you. Seemed reasonable to me, with my lack of experience. I didn't want a border, so saying 'colour it instead' and then making the colour like the text seemed reasonable to me. – Dr Darren Mar 4 '19 at 23:53
  • 2
    @DrDarren there is some cost to adding a colour, the resulting pdf will have code to push a colour on to the stack and restore it, just using the current colour, conversely a pdf link always has a border attribute so setting its width to 0 (pdfborder= 0 0 0) is a far more direct and lightweight way of specifyng this – David Carlisle Mar 5 '19 at 0:01
  • Thank you for that advice. All I can say is that I did what I did as a naïve user and to me it seemed logical. It is great to have so much expertise out there, and people willing to give their expertise. I wanted one kind of link to be blue and the rest invisible. Many thanks. – Dr Darren Mar 5 '19 at 22:47

To sum up, as noted above, adding


fixes the problem with using the dot in the hyperref options. There are other ways of getting the result I wanted that also do not throw errors; thanks to other posters.

Perhaps hyperref should load xcolor instead of color?

| improve this answer | |

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.