On a walk recently, my kids found an LED display sign and discovered on close inspection that they could see individual colored lights up close, while it looked like colors from a distance. They asked me how this worked and I explained that different combinations of red, green, and blue lights could make any color. It was an abstract idea to explain to them, so it occurred to me that I could make a little web page to demonstrate how it works. I prompted Claude:

My kids have discovered that screen combine red, green, and blue to make all other colors. Could you make an html page that demonstrates mixing those three colors? Have a slider for each color that shows the color that’s being added as well as the output color.

And the result is RGB Color mixer.