Blue-yellow? The bottom right image of the parakeet appears to be black, blue, gray, and white, with a blush of pink near the beak.
(It's just greyscale to me fwiw, as someone non-tritanopically (I've never been sure what, nor the optician, doesn't seem to be cleanly proto or deuteranomoly, perhaps some combination?) colour-blind viewing it filtered to simulate that. On some hand-wavey high level I lack the ability to see what's left after what I can see has been removed, I suppose.)