Okay kiddo, a color histogram is like a graph that shows how many colors are in a picture. Let's say you have a picture with a lot of green grass and some blue sky. The color histogram would show that there's a lot of green colors and some blue colors in the picture.
Imagine you have a box of crayons with many different colors. If you make a picture using only the green crayon, the histogram would be really tall at the green part and very short at the rest. If you use all the colors equally, the histogram would be about the same height for each color.
It might seem a bit boring, but color histograms are really useful for things like photography and image editing. They can help us adjust the brightness and contrast of a picture or even find similar images based on color.