This is some pretty impressive line work, and I would say a big improvement from what I saw of your earlier submissions. When it comes time to coloring these, make sure to keep the contrast between colors up and don't sacrifice your line quality. Practice matching your line quality as close to what you have on paper with some test images. Also, don't be afraid to give the backgrounds some character too with matching theme and complimenting color scheme. These are just my thoughts, so take them with a grain of salt, but I can see these turning out to be even better as you hone in your skills. Good job!