[{"_id":"Colorcode_1","Combination":[{"color":[{"mixture":["Red","Green"]}],"code":"Maroon"},{"color":[{"mixture":["Yellow","Green"]}],"code":"Light Green"}]}]

db.collection.update({"_id":"Colorcode_1","Combination.code":"Maroon"},[{"$set":{"Combination":{"$map":{"input":"$Combination","as":"elem","in":{"$cond":[{"$eq":["$$elem.code","Maroon"]},{"$mergeObjects":["$$elem",{"color":{"$map":{"input":"$$elem.color","as":"colorElem","in":{"$cond":[{"$reduce":{"input":{"$objectToArray":"$$colorElem"},"initialValue":false,"in":{"$or":["$$value",{"$eq":["$$this.k","mixture"]}]}}},{"mixture":{"$setUnion":["$$colorElem.mixture",["Blue"]]}},"$$colorElem"]}}}}]},"$$elem"]}}}}}])