Public domain photos

The image shows an old book with a black background and a variety of colorful circles on it. The circles are arranged in a pattern and there is text written on the paper. On the right side of the image, there is a color chart with different colors.

The image shows an old book with a black background and a variety of colorful circles on it. The circles are arranged in a pattern and there is text written on the paper. On the right side of the image, there is a color chart with different colors.Open in library