You b&w looks really cool <3 the thing is, you put way less details in the colored version.
In the black and white we see many details and textures in the bg that show the mood in the scene. Meanwhile in the colored version there's only one or a couple solid colors. You also add more details to the characters themselves in the shaded version.
I'm sure if you gave the colored version the same treatment you give the b&w one you'd get better results. If I were you I'd keep on with b&w for now and practice coloring when you get spare time from doing pages. Color gives another whole layer of depth to art, so I think it's worth it to try if it works with you (it's more time consuming tho, and it's obvious you can do wonders with b&w, so it's not a necessity, it's just an option)
I'm a newbie with comic making but I'll give you a couple examples from my comic

Here the character is scared. There's a lot of tension in the air. I chose to go with yellowish colors for this kind of situations, it's a sharp color (magic on my comic is related to a golden tone so it fits as well)
Here things are calmer now, he's with his mom and no one's in danger. I used two shades of green (his favourite color, and a peaceful one) to show the change of mood as well- In the first panel there's a gradient from light green to white with some white circles floating around, he's processing what just happened, he's confused but he knows he's safe because his mom is there so he feels calm. In the next one he remembers what he just went through so the bg becomes darker. I should've adjusted the character's colors to fit the mood as well, but welp x'D
In these panels, after some not so nice events (in which everything was colored with kinda dull colors) Arckan (the boy) is happy again, he has great friends who love him and take care about him so he's as happy as he could be. I used bright colors in the rest of the page as well and adjusted the character's so they matched the bg's.
The point is, colors can help convey feelings really nicely and make your pages pop up a lot, keep on with the great job and good luck 
((I hope it helped a bit and that it's all understandable, English is not my first language and I tend to mess up lmao))