IPA: //ˈkaʊntərˌʧeɪnd//
KK: /ˈkaʊntərˌʧeɪnd/
Having colors or patterns exchanged in a mutual way, often used in heraldry to describe a design where elements are swapped between two different colors.
The coat of arms featured a counterchanged design, with the lion in gold on a blue background and the shield in blue on a gold background.
Counterchanged → It is formed from "counter-" (meaning opposite or in return) and "changed" (from Old French *changer*, meaning to change). The word describes a situation where something has been changed in an opposite manner or in return to its original state.
Think of something being changed in an 'opposite' way ('counter-') — that's what counterchanged means.