Those lines are sometimes not visible in final product. When “saving for web” if you select “preserve art” rather then “preserve type” it makes the seams less noticeable.
To get rid of the seams select the color shapes on both sides and use Pathfinder>Unite.
You can use the Magic Wand tool to select all the light blue parts and then merge them together using Unite, then the dark blue.
Source : Link , Question Author : Andrea , Answer Author : Webster