how do we perceive 3 separate r,g,b colored regions as one single color

how do we perceive 3 separate r,g,b colored regions as one single color

Monitors display colors by flashing regions of reg, green and blue light, very very close to each other. Humans perceive the combination of the three colors as one, because limitation in the resolving power of our eyes.

This seemed very surprizing to me, so I wanted to find out if simply placing two different colored regions next to each other can make a new color. This app does exactly that.

There is a grid of squares, and the colors of each square alternate between two user defined colors. You can change the size of the squares. Once the squares are small enough, you actually perceive the two colors as one new color!

See how Red and Blue squares get smaller and smaller and turn into a new color: