If you'd really prefer to specify RGB colours in \hypersetup without loading the (x)color package, you can always type them in directly like this:
\hypersetup{colorlinks,breaklinks,
urlcolor=[RGB]{0,0.5,0.5},
linkcolor=[RGB]{0,0.5,0.5}}
Still, as Ulrike mentioned, loading xcolor is usually the more comfortable way to go. Although probably a little overkill for your problem, this is how I generally proceed:
\usepackage[dvipsnames,svgnames,x11names,hyperref]{xcolor}
Note that you can specify multiple colour name spaces so long as you're not too concerned about name clashes (otherwise read the rules about this in the xcolor manual). Since you're loading xcolor to fit in with hyperref, don't forget to include the [hyperref] option as you go.
The code adds some completely useless invisible (or rather white) stuff. The lines
\clip(0pt,403pt) -- (389.957pt,403pt) -- (389.957pt,99.6166pt) -- (0pt,99.6166pt) -- (0pt,403pt);
\color[rgb]{1,1,1}
\fill(3.76406pt,399.236pt) -- (380.923pt,399.236pt) -- (380.923pt,253.19pt) -- (3.76406pt,253.19pt) -- (3.76406pt,399.236pt);
\fill(53.4497pt,394.719pt) -- (374.901pt,394.719pt) -- (374.901pt,289.325pt) -- (53.4497pt,289.325pt) -- (53.4497pt,394.719pt);
draw a white background that is larger than the actual picture. TikZ sees that and thinks it is part of the picture. Simply removing/uncommenting these lines removes most of the whitespace.
Near the end of the first scope,
\color[rgb]{1,1,1}
\fill(3.76406pt,249.426pt) -- (386.193pt,249.426pt) -- (386.193pt,103.381pt) -- (3.76406pt,103.381pt) -- (3.76406pt,249.426pt);
does the same.
Additionally (near the end of the second scope),
\pgftext[center, base, at={\pgfpoint{220.95pt}{106.392pt}}]{\sffamily\fontsize{9}{0}\selectfont{\textbf{ }}}
adds a blank node below the picture, again enlarging the bounding box.
Removing all those lines gives a tight bounding box.
As far as I know, TikZ cannot do the cropping for you, as it can't know whether the white stuff is intentional or not (there might for example be a dark background behind the image so that white is visible).
Best Answer
In answer to your first question - mixing colours in (say) RGB format - you could use the notation similar to that specified in the
xcolorpackage documentation, since TikZ recognizes this. For example, mixing/sharing proportions of black green is obtained usingand displays
Or, if you're interested in mixing certain quantities of RGB colours, you can use a part-wise mix as follows:
which outputs
For answering your second question - dealing with boxes - you can use the
fancyboxpackage or evenPStricks. Here is an example using the latter: