I just installed and re-installed IntelliJ. Every Java file is coming up RED. I checked the JDK; it is at 1.6.##. The maven clean install build worked just fine
maven clean install
The issue was that the file I was trying to import was so large that IntelliJ wouldn't run any CodeInsights on it.
Setting the idea.max.intellisense.filesize option to a higher value as per the instructions on this answer resolved my issue.
idea.max.intellisense.filesize