One couple choose a red condom from a pack with one red, yellow and green. They talk about it being red, and about working their way through the rainbow. In a later scene they talk about not having made it to yellow, and the condom they have used is seen - a green one. Unless they also used a green condom having sex a second time, not in any way shown nor hinted at on-screen (which seems inconsistent with the rest of the movie), green is the wrong color.
The sperm sample in one of the early scenes is a container with the word "PERISHABLE" misspelled as "PERSIHABLE".