Labels for literals in sh:in enumeration

Hi all, 

What would be the best way to include labels to sh:in for literals? Using literals instead of resources is reasonable in some use cases. 

For example you might want to use literals for HTML colors and labels for the drop down menu: 
ex:InExampleShape
	a sh:Shape ;
	sh:targetNode ex:RainbowPony ;
	sh:property [
		sh:predicate ex:htmlColor ;
		sh:in (' #FDD7E4 ' ' #800080 ') ;
	] . 

instead of: 
sh:in ( ex:Pink ex:Purple ) ... 
... and something like ... ex:Pink rdf:value ' #FDD7E4 ' . 
There is of course many ways to model this but in case you need to use literals for simplicity the could be something like enumNames that is proposed to JSON Schema v5: https://github.com/json-schema/json-schema/wiki/enumNames-(v5-proposal) 

Best Regards, 
Miika Alonen 

CSC - IT Center for Science 
miika.alonen@csc.fi