I figure the kittens will be tabby and at least some of them will be orange. Not an expert, but somebody who knows more than me will weigh in on this, I'm sure.
If the girl isn’t too far along she can be spayed asap, the sire trapped and neutered as well, no need to contribute to the over population of moggies.
Colours will be red males, cream males if both carry dilute, black tortie females, blue tortie females if both carry dilute.
If both carry solid kittens can be solid or bicolour, otherwise tabbies with or without white.