diff --git a/cheatsheets.tex b/cheatsheets.tex
index 776b5c4..f5aedc4 100644
--- a/cheatsheets.tex
+++ b/cheatsheets.tex
@@ -149,7 +149,7 @@
 }
 
 
-\newcommand{\optional}[1]{\textcolor{gray}{#1}}
+\newcommand{\optional}[1]{\textcolor[RGB]{78, 78, 78}{#1}}
 \newcommand{\mandatory}[1]{\textbf{#1}}
 \newcommand{\parameter}[2]{%
   \expandafter\ifstrequal\expandafter{#1}{optional}%