Sure, here's a two-paragraph answer to the question, Why do 4K UHD Blu-ray movies have a different color appearance compared to 1080p Blu-ray?
4K UHD Blu-ray movies have a different color appearance compared to 1080p Blu-ray because of the way they are mastered and the wider color gamut they support. 4K UHD Blu-rays use a wider color gamut, such as REC2020, which allows for a greater range of colors between black and white, resulting in more lifelike and vivid colors. This wider color gamut is also known as HDR (High Dynamic Range), which allows for a greater contrast ratio between light and dark colors, making the image look more lifelike.
In contrast, 1080p Blu-rays use a narrower color gamut, typically the Rec. 709 color space, which doesn't support the same range of colors as 4K UHD Blu-rays. This means that when watching a 1080p Blu-ray, the colors may not look as vivid or lifelike as they would on a 4K UHD Blu-ray. Additionally, 4K UHD Blu-rays typically have a higher bitrate, which allows for more data to be used to represent each frame, resulting in a clearer and more detailed image than a 1080p Blu-ray. Overall, the combination of a wider color gamut and higher bitrate in 4K UHD Blu-rays results in a more immersive and lifelike viewing experience compared to 1080p Blu-rays.