Try using D19163 for the colour instead, and set the layer blending mode to Overlay at 200 Opacity.
Originally at the time of writing this tutorial I had assumed everyone had the same experience I had with Paint.NET. However, obviously there are a lot of newcomers to Paint.NET who may view this tutorial. In order to make this more newcomer friendly I'm rewriting this tutorial and may also provide a video if time permits. It will also include some improvements that I have thought of. Thanks for all the replies on this tutorial.