Lovely concept. The colours are very subtle. I feel that the light takes too much of my attention. I think this image would even work with the lights cropped out. You could crop to just outside the mans back and crop most of the top off to the height of the fence at the right of the image This would make the light on the man's back the brightest part of the image. Just a suggestion.
I see some purple in the sky but I don't know if it impacts the photo as much as it should for this challenge. It's a very nice night shot. I would only suggest cropping it to exclude the other wall or fence and the fishing gear.
Image is heavily oversharpened. Where is the purple? The sky or the chromatic abberation around the lights? Nice composition, could've been technically executed much better.