Nope! There is no way to know. Trigger was one of 3 black puppies in a 6 puppy litter. There were 2 fawns and a blue in the litter as well. One parent was cream and the other was a fawn. Thats part of the fun of chihuahuas
The best you can do is look at the two pedigrees you're considering breeding. If you're looking for a rare color like blue, its best to have one parent be blue. If you're looking for white puppies, its best to have both parents be white. Bryco has a ton of white dogs in his pedigree and I expect he will throw white puppies. Trigger has mostly fawns and blacks in his pedigree, he is neutered, but lets just say I'd bred him to a white female, who had blacks or tans in her pedigree...chances are puppies may be black or tan, less chance for a white. But color can "hide" for awhile...then appear in a breeding, a total surprise. The blue in Trigger's litter had NO blue ancestors in the 5 gen pedigree...so...??
Your best bet is to thoroughly research billa and the stud dogs pedigree, if the dogs aren't well shown or from a breeder who keeps note you'll struggle to find the info without contacting all the breeders.
I went through lotus' only got her mums side done so far but some lines I can get back another 5 generations
The only thing I know is a big no no is not to breed 2 dilutes together Dilute individuals carry a recessive genotype of dd and are characterized by blue, bluish-grey, lavender or flesh-colored noses, lips and eye rims. The coat colors may include blue, fawn, blue-fawn, bronze, taupe or some variation of these. Or 'self' colored are considered dilutes (don't have a black nose). That is one of the reason Zoey has so many health issues. Her dad was a chocolate and her mom was a blue fawn, but she had lots of dilute colors in her background on both sides.