There is no difference in insect tollerance based on hide color
Any animal may have a genetic predisposition for low insect resistance or high insect resistance
Breed difference has the greatest to do with insect tollerance, and it is brahmans and Zebu type that have the greatest tollerance for insects, they are also the largest breed world wide, just due to survivability
They are in Africa, Idia, Australia, brazil, Mexico, Argentina ect. ect.
Look at forage availability, climate, where there is poor forage, hot climate and lots of bugs you will find Zebu cattle all others have a hard time surviving. Just plain facts! Proof available! NO BS