Where is the legend?
What is the difference between the white/blue 3g, and white/blue 4gLTE?
Blue: data services connected
White: signal coverage available but not yet connected.
Basically you need blue to receive email, use the browser, etc.. White means your phone *should* be trying to connect fully.
to see the legend, open that little piece of bloatware in the app drawer called help center, click on the guide tab, scroll down and click on homescreen, then scroll down to smartphone status and notifications. there you have it.