These backgrounds are designed for use with the Textgram app for Android. They are 612 pixels squared like other Textgram backgrounds offered on this site.

I found these backgrounds on various sites. I cropped them and adjusted intensity of light or dark colours as I saw fit to make it easy to get high contrast text on it, with focus still left on the text rather than on the graphics. More colours will be coming, along with themed images or packages of mixed images. Enjoy!