What Causes Brown Fingernails By Birth?

hi doctor , i am confused becuase i keep getting different answers , my question is , we all know that ones finger nails is supposed to have the normail color like evryone else but my finger nails are brown/copper in colour, but the problem is i was born with it,my natural colour , but people keep telling that if ones finger nails are not the normal colour that means one is severly sick or has a health problem ,but am not sure since i and my dad are the only ones with this problem in my whole family.so i wanna know if its really genetic or its a health problem?