diff --git a/book/figures/flowcharts_tikz.tex b/book/figures/flowcharts_tikz.tex
index fdfa95f..c68219f 100644
--- a/book/figures/flowcharts_tikz.tex
+++ b/book/figures/flowcharts_tikz.tex
@@ -24,7 +24,7 @@
 
 \tikzstyle{BC} =  [decorate,  % Brace Calligraphic
                  decoration={calligraphic brace, amplitude=3mm, raise=1mm},
-                 very thick, pen color={black} ]
+                 very thick, pen colour={black} ]
 \tikzstyle{loop} = [arc, draw=codeblack, line width=0.4mm]
 
 \tikzstyle{timeline_event}=[align=center, fill=white, inner sep=2pt]