Looking closely, the second panel here contains every different colour I used in the same panel, except Razira’s dark green hair tie, and the yellow I blended into the gold for Konsi’s two-tone eye shade - so if you include those, it’s 27.
Coloursoft pencils are quite versatile in the range of shades they can produce - so (for example) all the different shades in the wooden beams are the same pencil - or all the different reflections on the silver parts of Razira’s dress are the same pencil.
I haven’t included the black of the ink pen or the pure white of the untouched paper in this count - or the digital watermark at the bottom.