All Texas Longhorns has one of three basic colors, red, black and wild gene and there are many other genes that influence coloration and complex patterns of white (unpigmented) hairs, spotting pattens, and reduction in pigmentation to produce orange, yellow, grulla and dun. (David M. Hillis)
I really taken to the true black, grulla, and dun cattle along because the look so cool and amazing. Actually all longhorns are cool. I think the best day is birthing day of calves because you never know what you will get from your breeding. We have 160 acres so the next thing is trying to find the cow and calf. The next best thing is discovering if they are a heifer or bull.
There are few ways cattle will be considered black.
Total black or black with white markings.
White body with black ears, nose, and other markings like blue roan.
Gorilla body or body markings no brown/red markings and there are many shades.
Not true black would be a Parker brown/Parker black cattle which could be black bodied or markings but brown ears, brown around the nose and other brown markings. They cannot produce black cattle unless bred with a black or grulla.
There are cattle who can be homozygous for black which means they cannot produce a red calf but only black and grulla. There is a small percentage who are homozygous.