core/src/main/java/io/fabric8/maven/core/util/ProfileUtil.java
private static List<Profile> readProfileFromClasspath(String name) throws IOException {
        List<Profile> ret = new ArrayList<>();
        ret.addAll(readAllFromClasspath(name, "default"));
        ret.addAll(readAllFromClasspath(name, ""));
        return ret;
    }
private static List<Profile> readProfileFromClasspath(String name) throws IOException {
        List<Profile> ret = new ArrayList<>();
        ret.addAll(readAllFromClasspath(name, "default"));
        ret.addAll(readAllFromClasspath(name, ""));
        return ret;
    }
Read all default profiles first, then merge in custom profiles found on the classpath