The “Shhhh….” color scheme is monochromatic. The shades of blue get lighter as the circles get bigger and darker the smaller the circles get. Each kind of blue has a kind of blue or white added to it which makes the blue either lighter or darker.
In “Seventies Citrus” the color scheme was analogous. As the colors get darker they turn from orange to yellow. Since orange and yellow are next to each other on the color wheel, this makes the color scheme analogous.