The blue/purple doesn't look too bad. I think it's the saturation of the marker's that overpowers the sketch mostly. I like to take a photo or scan of 1st sketches, reduce the opacity and print them out on A4 for a second pass sketch on top. Love to see you try a second pass to punch up your sketches because you're great at unique line work.
similar artist here. i am colorblind and the best solution for me is to head in with grey (watercolor, marker) to shade it and then color it using reference. Also, because you are so similar, I recommend trying brush pens
