I made my sample graphic using Adobe Illustrator, I created a new project, I used the lines tool to add four lines that went from each corner to the center creating an X shape, and then I used the elipse tool to create four circles from big to small, colored red being biggest, green being second biggest, blue being second smallest, yellow being smallest. After, I used the fill tool to fill in each circle, then I used the gradient tool to give the circles a black outline. 👍