A magenta gap in the colour wheel

A colour wheel shows colours on the circumference of a circle. The electromagnetic spectrum shows wavelengths on a linear scale. Magenta is in the first, but not in the second. Elucidating this seems important to understanding, and to teaching and learning.

[1]  Jay L. Federman,et al.  RETINA AND VITREOUS , 2018, Constable & Lim Colour Atlas of Ophthalmology.

[2]  L. Woolf.  Confusing color concepts clarified , 1999 .

[3]  L. Parsons.  As easy as R, G, B , 1998 .