Cool
The cool pastel shades of blue and purple are "COMPLEMENTARY" to one another, The pitch black background does not disturb this "WORKING-RELATIONSHIP" between the colors, but rather intensifies it, A horizontal layout of the image also benefits the chosen design, for it spreads it out entirely, Having a transparent purple hue on the top, and a transparent blue hue on the bottom, creates a contrasting look between the two shades, This as well, does not take away from the quality of the image.
~~THINGS TO IMPROVE ON~~
This was an amazing design here the purple is amazing I think some added flow on spots would give it a nice luminating effect.
~X~