Unfortunately there are too many complementary pairs here to demonstrate the effect of one colour contrasted against its opposite. If the bird's eye and beak could have shown more orange against the blue feathers on its head, that would have been a great demonstration of complementary colour contrast.
Nevertheless, this is a great photo of a colourful bird.
I'm new to this forum but I've noticed colorful bird shots often do well. That said, this one is truly brilliant. Love the emotional connection with the bird's eye. Can we make his head green rather than blue to highlight the color complement? Just kidding - great shot!
...are not complements. By the way, there are lot of color pairs that are in harmony to my personal taste. Anyway, learning color circle and some color mixing theory was useful. That is why I liked this theme of challenge.