refs #8381. Refactoring and fixes.
refs #8381. Fix tests.

Some of the CompositePeaksPresenter tests were broken by the previous changes.
refs #8381. Extend python tests and fix bug.

Bug was causing the 'Hide' button to get activated for no reason.
refs #8381. Change to American English.

Color is more consistent in the python API. Since this interface is being exposed via SIP. It makes sense to rename the colour functions.
refs #8381. Update sip documentation.