This image is an RGB color image with blended in Ha (H-Alpha) data. The H-Alpha data primarily shows the nebula itself while the RGB information is used to color the stars. To get the luminence for this image, I used the Ha data instead images from the monochrome luminance filter. This is because when I tried blending with data from the L filter, the stars became bloated and the nebula was quite faint. So using Ha as a synthetic luminence plane worked much better.