Example written in answer to the question Click How to change the color of a circle annotation?
circleannotation
##GITHUB:https://github.com/itext/itext-publications-examples-java/blob/master/src/main/java/com/itextpdf/samples/sandbox/annotations/CircleAnnotation.java##
##GITHUB:https://github.com/itext/i7ns-samples/blob/develop/itext/itext.samples/itext/samples/sandbox/annotations/CircleAnnotation.cs##