North American Colias ID question

[akcolias]

I have a question for someone more experienced with North American Colias.  I have a selection of yellow Colias that were caught in alpha fields in Nebraska, in early October.  Most of them have orange hind wing spots, and I think they are Colias philodice.  However, about 10 percent of them have white spots, usually with a reduced forewing dot.  I am wondering if these are a different yellow sulphur, or just a range of variation in C. philodice.  There may be hybrids with C. eurytheme confusing things as well, as they were very common in the fields at the same time.  Hopefully the pictures I have attached below come through.  Thanks for any insight. 

[bobw]

They're almost certainly philodice, but a photo of the underside would confirm it. They are quite variable.

[akcolias]

The undersides do appear quite similar.

[akcolias]

well that was because they were the same picture twice.  Here is the one with the orange spot

[bobw]

Yep, they're all philodice.