Okay, so I tried coloring the page, which gave me a slightly better understanding of what kind of approach it would require, I hope. First of all, though, I really like your lineart, it has clear silhouettes and composition, and some of that I think got lost in the coloring.
So I was trying to color while maintaining contrast of the grayscale picture. Which is pretty much what coloring is all about anyway, in my opinion, though here it was a little more difficult since your lineart is a mix of flat black and white, but also gray and actual grayscale in the clouds.
At the same time I think the colors you used were a bit too saturated. Not that you should only use dull colors, but on a blue background even gray-ish red will stand out.
Okay, so,here's my attempt:
As you can see, I was trying to maybe add a little depth to the first panels, and variation in color.
Now, for the last one. I was trying to render the face area as much as possible, and left the rest in the shadows. That is, seems to me, what was distracting about your color version, like with the lineart, you made the face simple and the clothing detailed. And with lines it's a good thing (especially since you draw manga), but with colors not so much.
I made a grayscale screenshot of the colored version. as you can see the contrast is more or less maintained. This is something I'm still learning myself, it can be tricky. If you're using photoshop, there's a way of setting a ctrl+Y shortcut to quickly preview how your values look (at the bottom of the linked page)
I'd also like to point out how in the screenshot you can see the PS color picker. The more saturated color (top right) is somewhat darker than white. This is why your first three panels were hard to read, you used a strong blue for the sky, and it darkened everything.
And to point out again, I actually used some strong colors, but either dark or darkened by the lineart's gray elements, they are not as noticeable/distracting. Also, I have a basic palette of colours that I always use, so I spend less time trying to pick the right combination. Took me a while and some trial and error to set it up, though.
Anyway, going back to your original question,I prefer to read comics in color. Maybe because I grew up with western comics rather than manga, either way, I think that if you have the time to color your work, it's usually worth it. It's just that coloring requires planning differently.
It goes the other way too, I have issues with linework, I have a hard time getting into the right mindset with it.
I hope this was somehow helpful, and good luck with your project!
