Remove ugly borders around clickable cross-references and hyperlinks

With \usepackage[hidelinks]{hyperref} you get active links in \textcolor (usually black) without a box around them.

I use something like

\usepackage{xcolor}
\hypersetup{
    colorlinks,
    linkcolor={red!50!black},
    citecolor={blue!50!black},
    urlcolor={blue!80!black}
}

This gets rid of the ugly color boxes, but uses dark colored fonts which still make it clear that they are clickable.

Well, I see there are a lot of answers already, and they work, however I thought I'd give more detail:

As above, you can use

\usepackage[hidelinks]{hyperref}

or

\hypersetup{hidelinks}

However, if your problem is with the ugly green boarder there are very nice ways to remove that, without making it unclear what is a hyperlink.

I like

\hypersetup{
  colorlinks   = true, %Colours links instead of ugly boxes
  urlcolor     = blue, %Colour for external hyperlinks
  linkcolor    = blue, %Colour of internal links
  citecolor   = red %Colour of citations
}

That should be pretty self-explanatory, since I've commented everything so I can keep track of it.

There is also

\hypersetup{frenchlinks=true}

Which replaces the colour with small caps. No idea why it is French, or why small caps, but it is also an option.

There, I felt this helps complete the above answers; Yes, you can remove the box by hiding all the links, but there are other choices out there.