Today I did one of our mini assignments that challenged me to create a signature background. There was a couple of things I had to do but I made a canvas of 400x400 and then used the gradient tool and just started to cross it all while in the colors of black and white. And then I went to filter> distort> wave and did that 5 times over and over and clicked randomize each time and them got that. I pressed Ctrl+U and then the Hue/ Saturation bar pulled up and pumped the settings to 205 and 50 and picked the color purple and then BAM! The end product. Hope you enjoyed.