A: 

On mine, 09 is an error. JLS§3.10

Yes, but something like 012345 isn't.

Ah, this is an excellent point, but it seems isomorphic to the problem of highlighting any numeric literal, which is supported as an editor preference. In Java, this is enhanced by the convention of using all capital letters for the identifiers of immutable constants. I would argue that all numeric literals be treated with equal suspicion.

trashgod
Yes, but something like `012345` isn't.
polygenelubricants
+4  A: 

No, currently you can only configure a color for all Numbers in Preferences > Java > Editor > Syntax Coloring. May I suggest creating an enhancement request at the Eclipse Bugzilla at http://bugs.eclipse.org/ (correct project is imho JDT / text)?

Ralf Ebert
@polygenelubricants if you do post an enhancement request, please put a link to it, here.
MatrixFrog