<story><title>Why does the chromaticity diagram look like that?</title><url>https://jlongster.com/why-chromaticity-shape</url></story><parent_chain></parent_chain><comment><author>GrantMoyer</author><text>In my opinion, plotting chromaticity on a Cartesian grid — by far the most common way — is pretty misleading, since chromaticity diagrams use barycentric coordinates (and to be clear, I blame the institution, not the author). The effect is that the shape of the gamut looks skewed, but only because of how it&amp;#x27;s plotted; the weird skewedness of a typical XYZ chromaticity diagram doesn&amp;#x27;t represent anything real about the data.&lt;p&gt;Instead, a chromaticity diagram is better thought of as a 2D planar slice of a 3D color space, specifically the slice through all three standard unit vectors. From this conception, it&amp;#x27;s much more natural to plot a chromaticity diagram in an equilateral triangle, such as the diagram at [1]. A plot in a triangle makes it clear, for instance, that the full color gamut in XYZ space isn&amp;#x27;t some arbitrary, weird, squished shape, but instead was intentionally chosen in a way that fills the positive octant pretty well given the constraints of human vision.&lt;p&gt;[1]: &lt;a href=&quot;https:&amp;#x2F;&amp;#x2F;physics.stackexchange.com&amp;#x2F;questions&amp;#x2F;777501&amp;#x2F;why-is-the-visible-light-spectrum-different-to-a-hue-wheel&amp;#x2F;777566#777566&quot; rel=&quot;nofollow&quot;&gt;https:&amp;#x2F;&amp;#x2F;physics.stackexchange.com&amp;#x2F;questions&amp;#x2F;777501&amp;#x2F;why-is-th...&lt;/a&gt;</text></comment>
<story><title>Why does the chromaticity diagram look like that?</title><url>https://jlongster.com/why-chromaticity-shape</url></story><parent_chain></parent_chain><comment><author>hoherd</author><text>Here&amp;#x27;s another really interesting exploration of color spaces &lt;a href=&quot;https:&amp;#x2F;&amp;#x2F;ericportis.com&amp;#x2F;posts&amp;#x2F;2024&amp;#x2F;okay-color-spaces&amp;#x2F;&quot; rel=&quot;nofollow&quot;&gt;https:&amp;#x2F;&amp;#x2F;ericportis.com&amp;#x2F;posts&amp;#x2F;2024&amp;#x2F;okay-color-spaces&amp;#x2F;&lt;/a&gt;</text></comment>