As I (mis)understand it, you can create the wavy boundaries with the Zig Zag Effect with Smooth Points (Effect dropdown, you can get different sizes/shapes), and apply normal fills.
I would create a star with the appropriate number of points, round the points with the direct selection tool.
Create your other shapes and use the original as a clipping mask.
Note: I did not try to dupe the hair shapes exactly.
As Jacob mentioned, to create those wavy paths, I would use Effects>Distort>Zig Zag.
To “color inside”, I used Live Paint.
Here I applied Zig Zag to a circle.
Next, duplicate those circles.
Next, Live Paint.
Expand Live Paint.
Delete Strokes, Pathfinders panel, select same colors, Unite.