Both film and digital cameras, by no mere coincidence, respond to the same basic three colors the cells in our eyes do - red, green and blue - so they essentially see the same thing our eye does.

When those images are displayed back to us, our vision system responds to certain proportions of red green and blue as all of the colors of the rainbow, so to speak.

When you look at something emitting a pure yellow frequency, your eyes don’t actually record yellow, it records a certain amount of green and a certain amount of red (and technically probably a certain amount of blue because there is a lot of overlap between the three kinds of receptors and red even actually wraps around and has a little hump in the blue spectrum giving you purple) and your vision processing center interprets that as yellow. If you display red and green light together at the same proportions, your vision system will see that as the same yellow and not know any better.

That’s what the screen you’re looking at right now does - it’s just a bunch of tiny red, green and blue lights shining at different places at different proportions to recreate all the colors you’re seeing.