Have you seen pictures of their dad? He is NOT a snow white Italian, but closer in complexion to Frankie.
Of the three you can see that, Frankie is the darkest, and that is NOT a tan. Frankie resembles both his granda (facial features) who has whiter skin and his dad whose skin tone is shade or two beyond olive. Everyone is getting thrown off because the mom (Victoria) has make up caked on that is lighter than her actual skin tone and has dyed her hair blonde.
I recall their aunt (mom's sister) ranting and raving on TV when John Gotti was convicted some 10 years ago. She doesn't have a snow white complexion either but is olive toned. So there is "color" in the family GOTTI family line. The uncle Pete who came to dinner wasn't snow white either. John, Jr. Victoria's other brother however, is more on the white side.
It really doesn't matter what generation one may be...if there any relatives with darker tone skin, ANY off-spring can come out with dark skin. I should know. I'm African-American. Among my 7 brothers and sisters, there is a variance of tones, and we ALL have the same parents.