When translating projects with index entries, the colons can really get in the way of term recognition:
As a work-around you can add the colon (U+003A) to the Additional space characters and remove it from the Do not match characters:
Note: Please don't forget to put everything back once you've finished your project.
BTW: You'll have to insert the colons manually!
It's easy to forget an (important) colon, so perhaps the best approach is to clear the target, transfer the source via the green arrow and then manually insert all recognised terms.
To make thinks really complex: in order to check whether you've forgotten to insert a colon, you could replace all colons in source and bracket with () or )) or (( and QA for brackets. Afterwards, you'll have to restore everything.
A lot of working around.