Custom Image Placeholder is, as the name suggests, an API serving image placeholders for web developers (i.e. placehold.it | lorempixel.com). You can specify width and height, colors and a custom text via url and it will generate a placeholder for you.
This service was built while I was playing around with Play, an open source web application framework, written in Scala and Java. I set it up on my server and I use it to this day.
Just create an URL like this:
without a color, to get a white background, or
giving the hex of it.