Why can the exact same color look like two different colors?
A gray that looks pale on one background turns dark the moment you move it onto another.
Your eyes never read a color on its own - they read it against whatever surrounds it. The same patch looks lighter on a dark background and darker on a light one, and its hue shifts away from the surrounding color too. This is simultaneous contrast, and it happens because vision is built on comparison, not absolute measurement: the brain pushes a patch's lightness away from its neighbors and pushes its hue toward the opposite of the surround.
A beige sofa looks warm and creamy in the bright showroom, then turns dull and grayish at home against your dark wood floor - same fabric, different neighbors.
Color is judged relative to its surroundings, so the background can change what you see without the object changing at all.
When you pick paint, tiles, or an outfit, judge the swatch in the real setting it will live in - the wall or skin next to it will shift the color you actually get.
Same paint, new neighbor, new color. Your eye compares, it doesn't measure.
Learn the idea and practice English at the same time.