The Cal White hens are quite a "hodgepodge" genetically, but they contain only 1 copy of dominant white. The White rock has recessive white, which means his white "probably" has no influence in the chick's down color (unless the Cal white also had a copy of recessive white passed down from it's white leghorn parent - no way to know that).
The 2 yellow chicks are heterozygous (1 copy) dominant white. This usually shows some leakage of the underlying color, possibly black). Or, the yellow chicks could be homozygous recessive white. In any case, you will not be able to infer the sex of those 2 from down color.
Now, the black ones are more interesting. The female parent had one, or 2 copies of sex linked barring. But unfortunately, you can't be sure the white rock male was free of barring, though of the chicks are not barred, he had at most 1 copy. In the end, without knowing the underlying genotype of the Cal Whites leghorn parent, you cannot be sure of the sexes of any of the chicks based on down color.
This is why most people will tell you a white bird cannot be used for sex linked hybrids. Unless you are quite sure of the genes they carry for barring and extended black or gold/silver, you will not be able to ensure the correct parent is used for each sex.
