Chapter 4 Appearance

4.1 Formatting variables

4.1.1 Colours

Type the name of the colour you want after the name of the variable like this:

  • You can use all the HTML colour names like black, white, skyblue etc. You can use transparent too.

  • These colours: red, orange, blue, green, grey, purple are special because if you put a number from 1 to 9 straight after these names, like orange3, you get nice shades which all fit together.

  • … whereas white and black can be made variously transparent in the same way, by adding a number from 1 to 9. So white1 is a very transparent white, black7 is a fairly opaque black.

If you want a colour which fades from left to right, try something like blue2:red3 or white:snow. Please don’t even try anything like red:blue. You have been warned.

You can even use HTML colours:


… and you can add two additional digits for transparency:


4.1.2 Fills and borders

color= refers to the colour of the edge. If you want to have the main body coloured differently from the edges, you have to put something like this:

… and you can adjust the thickness of the “pen” which draws the border with something like penwidth=4.

4.1.3 Other ways to format variables

You can tweak the appearance in other ways too like this:

My variable;  fontcolor=green2;  fontname=Courier;  fontsize=22

Some possibilities:

shape=oval              # also none, circle, diamond, square
style=dotted,filled     # also dashed,filled etc
height=.2; fontsize=8   # height can be larger but not 
                        # smaller than required by the text, unless you 
                        # set fixedsize=true
style=striped,filled;fillcolor=red2:red3:red4   #amazing!                

4.2 Formatting arrows

You can also try these:

direction=both  (back, forwards, both or none)



taillabel= my tail label

headlabel= my head label

4.3 Fontnames

You can use any fontnames installed on your computer, but they might not look the same on another computer.

4.3.1 Fonts which work everywhere:

AvantGarde-Book AvantGarde-BookOblique AvantGarde-Demi AvantGarde-DemiOblique Bookman-Demi Bookman-DemiItalic Bookman-Light Bookman-LightItalic Courier Courier-Bold Courier-BoldOblique Courier-Oblique Helvetica Helvetica-Bold Helvetica-BoldOblique Helvetica-Narrow Helvetica-Narrow-Bold Helvetica-Narrow-BoldOblique Helvetica-Narrow-Oblique Helvetica-Oblique NewCenturySchlbk-Bold NewCenturySchlbk-BoldItalic NewCenturySchlbk-Italic NewCenturySchlbk-Roman Palatino-Bold Palatino-BoldItalic Palatino-Italic Palatino-Roman Symbol Times-Bold Times-BoldItalic Times-Italic Times-Roman ZapfChancery-MediumItalic ZapfDingbats

4.3.2 Other fonts which work nearly everywhere include these:

  • Arial
  • Verdana
  • Impact
  • Comic sans MS

4.4 Standard graphviz tweaks

Lines like these below only apply to the diagram itself, like the background colour etc. You can precede them with diagram; like this:

diagram;  bgcolour=grey

4.5 Tweaks which go in lines on their own

proportion=1     # tall and thin or short and fat diagrams. `.1` is very short, `2` is very tall.    Alias for `ratio`.   

direction=TB     # top-down. Also, BT, LR or RL

label=My title   # adds a title to the whole diagram

layout=neato     # if you don't want a hierarchical diagram, try this!  
                   Also: circo dot fdp neato nop nop1 nop2 osage patchwork sfdp twopi

4.6 Also try these

nodesep=.1       # moves variables closer or further apart

ranksep=2        # try it and see!

orientation=L    # flips the diagram 90 degrees

splines=false    # keeps the arrows straight. Also try: `polyline`

4.7 Hardcore

If you really want, you can tweak any part of your diagram with most of the Graphviz attributes from label positioning to URLs. Not all of them will work – try and see.

4.8 Special Theory Maker tweaks

wrap=20          # changes the line wrapping in labels

4.9 Improving readability

4.9.1 Proportion

Type a line like:


4.9.2 Direction

Write a line like:


TB= top-to-bottom

LR= left-to-right


4.9.3 Variable separation

Moves variables further apart:

graph; nodesep=2. 

Closer together:

graph; nodesep=.01`