For making corrections, it's handy to be able to produce a subset of the slides in your file. The command
\onlyslides{4,7-13,23}
in the root file will cause the following \blackandwhite and \colorslides commands to generate only slides numbered 4, 7-13 (inclusive) and 23, plus all of their overlays. The slide numbers in the argument must be in ascending order, and can include nonexistent slides---for example, you can type
\onlyslides{10-9999}
to produce all but the first nine slides. The argument of the \onlyslides command must be non-empty.
There is also an analogous \onlynotes command to generate a subset of the notes. Notes numbered 11-1, 11-2, etc. will all be generated by specifying page 11 in the argument of the \onlynotes command.
If your input has an \onlyslides command and no \onlynotes command, then notes will be produced for the specified slides. If there is an \onlynotes command but no \onlyslide command, then no slides will be produced. Including both an \onlyslides and an \onlynotes command has the expected effect of producing only the specified slides and notes.