Many people wondered how they had such amazing colors for the plant life on the planet thinking they had colored them but it was done with a filter.
Originally, Crichton was still conscious after Aeryn punched him. But Ben Browder protested, saying there's no way his character would voluntarily get on the prowler with Aeryn, after she had assaulted him. So they rewrote it so that Crichton would be knocked out cold.
The small injector device is a modified nozzle/trigger for a compressed air duster gun. Such guns are used to blow clean, blow dry, or blow cool small things in light industry settings.