analog means that with a modulation input you can modulate the power of your laser for example 5v is full power and the lower you go the less powerful it is this is used in projectors for color mixing. but to be clear the 5v etc is just a modulation input thats not what the laser itself is powered by
TTL R-G & B can also give you teal- yellow and magenta.
six colors plus white if you have a good balance to start with...
Analog allows for full color- thousands of variations.
including white.
Cheap China projectors use TTL lasers and stepper motors. beams OK... animations and graphics not so much.