I'm having issues, too. I changed a couple email addresses in my GMail account online. I was looking for a way to re-synch the nook color to make the corrections as well. Unlike Contacts in Gingerbread rooted nook colors which have a tab to touch for re-synching, the stock B&N Contacts doesn't seem to have one.
My guess then was to go to Settings, then Social (under App Settings), then Unlink Your Account (under Google).
When I do this, I can check my Contacts and see that they're now gone.
Then I repeat the above procedure, except that the last step is Link Your Account (under Google). With this, I expected to see my Contacts reappear as corrected, but the corrections are not made.
I even powered the nc down and restarted it, but I'm not getting the new Contact information from Google's GMail to appear.
Is this a known issue or are we missing something on the nook color?