Hi Kayla--
Is the reddish color sort of underneath Chewy's topcoat, like there's the black and then below it some red-black? If so, she's got a coat similar to my Australian Shepherd's. Eli is a purebred black tri Aussie with a jet black topcoat, but there's areas underneath that are a little reddish. His breeder said that in sunny climates the black undercoat turns a bit red, that it's totally normal. (She has a champion black Aussie who's quite red during summer!) No big deal, and nothing that would make Chewy any less of a purebred Border Collie, I'm sure!