Angus cattle can be black or red. Red’s a recessive gene in the breed. The vast majority here in Ireland are black, but reds are getting somewhat more popular. There’s no difference aside from the hair/skin colour. I prefer the reds because they’re nicer to look at.

A lot of breeds that can be black can also be red, like friesians, highlands, droimeann, etc. But there’s other ones that are only red, because red to red only breeds red (while black to black can breed red if they’re both carriers of the red gene)

In the US (maybe elsewhere too?) the reds and blacks are registered as different breeds but that’s stupid. It was just started for the sake of “breed uniformity”