A couple of items (the color isn't, we wanted regular e-liquid to be noticeable for people who switched bottles for their daily use to be able to tell what they put into it)
The first I can think of is, the VG as apposed to the PG. VG will make the flavor slightly sweeter. The second, which nic liquid your mixing it with, the stronger the base e-liquid usually the more of a hint of the base tobacco "flavor" since most places use extracted tobacco nicotine. When you smell unflavored eliquid it usually has a noticeable smell to it, it also has a hint of taste. This can also change the taste depending on the amount of nic you use, or none at all.