Let me assure you guys that this is not a bug. The difference is a result of using different tile templates. The two notable ones you will see are Iconic and Flip. Here is the boiled down explanation of how each work and why you see a difference:
When you begin rearranging your tiles, the OS makes each element of the tile semi-transparent.
-Flip tiles can contain a text element and an image element as the tile's background. So a semi-transparent white pixel within that image will take on some color from your phone's background color (black or white.)
-Iconic tiles take a text element, a large number element (not relevant in this case), a tile background color as the tile's background element, and an image as the tile's icon element. The icon element is above the tile background color element which is above the phone's background color. In this case, the tile's background color (let's say blue) will have a little black or white because it's transparent. But then, the icon image, which is white, will have a little red from it's tile background element.
System tiles mainly use iconic tiles while many devs use flip tiles since it's easier and it's the default.