\document
\typesystem#color
	\struct#color
		\field#r[type=int]
		\field#g[type=int]
		\field#b[type=int]
	\constant#green[type=color, value=[r=0,g=255,b=0]]
	\constant#red[type=color, value=[r=255,g=0,b=0]]
	\struct#multipleColors
		\field#c1[type=color,default=green]
		\field#c2[type=color,default=red]
\ontology#test
	\struct#test[root=true]
		\field
			\childRef[ref=a]
			\childRef[ref=b]
	\struct#a
		\primitive[type=color]
	\struct#b
		\primitive[type=multipleColors]

\begin{test}
	\a{red}
	\a{green}
	\b{[c2=[100, 20, 30]]}
\end{test}