Nice as this is to be in color... isn't the order messed up? For example 17, 18, 19 should be 18, 17, 19. 34 and 33 also need a flip, and 1, 2, and 3 are also out of order.
Base +6, deltablu +6, Majorfoxy1990 +6, Gremrock +6
Download Krita (it's free, you have no excuse not to use it, and if you're using another program with the same capabilities or better, you can STILL do this. The only program it won't work on is basic Paint)
Take the layer with the lines on it and duplicate it. Set the higher layer to Multiply instead of Normal.
Create a third layer BETWEEN the bottom linework layer and the top linework layer, so you have the Normal linework on bottom and the Multiply linework on top with a blank layer in the middle.
Now paint on the middle layer. Doing this will allow you to color it in all the way without ruining the lines. The way you're doing it now just results in really scratchy results that don't look good, cause you're making the lines look all jagged and leaving little white pixels all over the place where the Bucket tool didn't color it right.
So just... stop doing it that way and stop using the Bucket tool.