True Tone is a technology that adjusts the color and intensity of the display to match the ambient light, so that images appear more natural. It is available on various Apple devices, including iPhones, iPads, and Mac computers. Here are some details about True Tone on iPhones:

• Positive: True Tone uses advanced sensors to adjust the color and intensity of the display to match the ambient light, so that images appear more natural. This can reduce eye strain and make the display easier to view in different lighting conditions.

• Negative: Some display accessibility settings, including Invert Colors, Grayscale, and Increase Contrast, might turn off True Tone.

• Product details: True Tone is available on iPhone 8 and later, iPhone SE (2nd generation) and later, iPad (9th generation), iPad Pro 12.9-inch (2nd generation) and later, iPad Pro 11-inch, iPad Pro 10.5-inch, iPad Pro 9.7-inch, iPad Air (3rd generation) and later, and iPad mini (5th generation) and later.

In summary, True Tone is a display technology that adjusts the color and intensity of the display to match the ambient light, and it is available on various Apple devices including iPhones. It can reduce eye strain and make the display easier to view in different lighting conditions, but some display accessibility settings might turn it off.