About: http://webisa.webdatacommons.org/453980008

Property	Value
http://www.w3.org/1999/02/22-rdf-syntax-ns#type	http://www.w3.org/ns/prov#Entity
http://www.w3.org/ns/prov#value	And you are right, if there are colors other than gray or black the spot is hardly, if at all, visible.
http://www.w3.org/ns/prov#wasQuotedFrom	ecoustics.com