What is hue in photography?

To me hue is the same as color. It may not be entirely correct, but this definition works for me as a photographer using Lightroom and Photoshop.

The hue sliders in Lightroom.
The hue sliders in Lightroom.

To me hue is the color in its purest form. If you look at the sliders in the image above, I can take Magneta at the bottom to become red if I pull it to the right or more purple if I pull it to the left. This is changes to the color as such in its purest form. Notice that each color slider picks up where the previous left, if you go from top to bottom.

You can saturate the color more or less or change the luminance (add white), but this is a different dimension than the color as such. When you change the saturation or the luminance, the hue remains the same.

Related reading

What is monochromatic colors?

What are complementary colors in photography?