How is the memory on the hard drive based on magnetization can display photos and videos that requires color?

How is the memory on the hard drive based on magnetization
Can display photos and videos
that requires color?
Don't you need to take care at the pixels and determine the colors of rgb (red green and blue)
at the range of:
0-255 for every color and every pixel and pixel separately ?

Don't you need to care of every pixel alone?
and determine the colors of RGB
at the range of 0-255?

Everything is numbers, stored as binary - text, programs, images, sounds, it's all just binary data whether in RAM or stored on a hard drive.

For images, each 0-255 range is stored as an eight bit binary number, a byte.
Eight 1s & 0s; 24 bits, three bytes for an RGB pixel or or 32 bits / 4 bytes for each RGBA pixel, with an "Alpha" transparency value.

It's down to the programs to use the stored numbers in the correct way.
Most types of files on PCs, other than plain text, have a header section that gives information about the rest of the content and how it is organised, to help ensure it is used correctly.

RGB is not the only way to represent color.

Also look here: https://99designs.com/blog/tips/correct-file-formats-rgb-and-cmyk/