I'm sorry to keep asking you try things, but we're fairly stumped by this one. Using a default config, can you create a workspace as follows:
1) Select Project > New
2) Click the Cancel button in the "New Project" wizard.
3) Expand the "C/C++" node in the Project type tree and select "GNU C/C++ Wizard"
4) Enter a Project name, Location, and leave "Create new workspace" selected.
5) Click "OK".
6) In the wizard, select "Executable" for the project type and "C++" for the Source type.
7) Click "Next"
Select "A 'Hello World' application" for Application Type.
9) Click "Next"
10) Leave "Build without a makefile..." selected.
11) Click "Finish" and then click "OK" on the screen that reviews your choices.
This creates a very basic C++ application. First try paren matching. Position the cursor near the braces and see what happens. Please post a screen shot if you are getting weird colors again.
Next try syntax expansion. Insert a new line at the top of the main function. Type "if" followed by a space. Post a screen shot of the result.
We'll want to use the default config and this basic workspace as the primary testbed to figure out the problem. It cuts down on the number of things we have to explore.